Mutations

Mutations are extra abilities that are given to you at the end of a level if you have leveled up. To level up you need to get 60 Rads multiplied by your current level number, which means the amount of Rads required increases with the character's level (60, 120, 180, etc.). Each level up is signified by a white crown symbol, appearing above your character. Going over level 9 and essentially reaching level 10 (Level Ultra) allows you to choose one of the character-specific Ultra Mutations listed below the regular Mutations table.

Mutations table

A list of all the mutations in alphabetical order. At the end of a level you can choose between 4 randomly rolled mutations per level up. Currently the game allows players to reach level 10, which means a total of 9 mutations. (Or 10 mutations if you take the Crown of Destiny, 11 if you also picked Patience)

In Co-op picked mutations will affect both characters.

Mutation	Icon	Description
Back Muscle		Bullet capacity increases from 255 to 555 and all other ammunition's capacity increases from 55 to 99. The game still uses normal capacity values to check how much ammo percentage you have and to calculate the pickup drop rate.
Bloodlust		Gives you a 7.69% (1/13) chance of regenerating 1 HP when you kill an enemy.
Boiling Veins		You take no damage from explosions when at 4 or less HP. It also nullifies any fire damage. To clarify; if you are damaged by an explosion at above 4 health, you will end up with no less than 4 health. (Explosions and fire cannot kill you.) Melting will be immune on full 2/2 health with this mutation, but if you have Rhino Skin it will work like it does with the other characters.
Bolt Marrow		Bolts and splinters seek enemies, changing the direction if close enough. Larger bolts from Heavy Crossbows will have a weaker homing effect. Seekers will home from further away, and take much sharper angles. Discs slightly change their direction and slowdown to hit an enemy multiple times.
Eagle Eyes		Increased accuracy, meaning less bullet spread. For example, SMG projectiles will fire in a straight line. Reduces fixed spread for weapons like the Triple Machinegun, Shotgun, Super Slugger, Super Crossbow, Splinter and Seeker weapons, and the Shovel. As a result, their projectiles are grouped tighter together. Steroids will still be less accurate tha other characters, although still more accurate than another character without Eagle Eyes
Euphoria		20% slower enemy bullets. Synergizes well with Eyes's active ability.
Extra Feet		Movement speed is increased. Additionally makes you walk normally on all surfaces. That includes spider webs in Crystal Caves and ice in Frozen City.
Gamma Guts		Touching enemies makes them take 6 damage per hit animation, for as long as your character is in contact with them. You will take no contact damage from enemies that are instantly killed by Gamma Guts (have 12 or less health at the moment of impact, as it takes two frames for enemies to deal contact damage with Gamma Guts). If an enemy is killed by Gamma Guts, your character will create an area of effect blast which deals 8 damage to all nearby enemies. Can also be used as a last resort if you run out of ammo and don't have a melee weapon.
Hammerhead		Pushing against a wall allows your character to break through exactly 20 wall tiles to create instant cover, or ambush enemies. You can also break Fire Traps by walking into them. The amount of tiles you can break resets back to 20 each time you enter a level ending portal.
Heavy Heart		Rate of weapon drops from enemies is increased by 210%. If an enemy has 2% chance to drop a weapon, with Heavy Heart that becomes 2%+2*210%=6.2%. Heavy Heart will only appear after you've picked your third "weapon type specific" mutation (Recycle Gland, Shotgun Shoulders, Bolt Marrow, Boiling Veins, Laser Brain or Long Arms) and won't appear again. It's not a part of the usual mutation pool.
Impact Wrists		Makes corpses fly much farther and faster, and they do more damage on impact.  Regularly, a corpse does 1 damage on impact with an enemy. With this mutation knocked away corpses do 2 damage + damage based on how fast they are going.
Laser Brain		Energy weapons have the duration and size of their attacks increased by 20%, meaning they will hit the target more times. Laser beam gets wider, lasts longer, dealing 2-14 damage. Addittionally, the Laser Cannon fires two more beams per burst. Plasma spheres get bigger and takes longer to shrink. A small plasma projectile deals 4-24 damage. Big plasma projectile fired by the Plasma Cannon deals 17-86 damage. The main plasma projectile fired by the Super Plasma Cannon deals 28-149 damage. Plasma Explosions are not affected by this mutation. Plasma Explosive weapon's damage does't change but Devastator's trail is 40% slower, which means more explosions. Lightning rails last longer, dealing 7-21 damage. Projectile fired by the Lightning Cannon deals 50 impact damage. Energy Melee slashing projectile lasts longer so it can hit the target twice, and is slightly bigger.
Last Wish		Choosing this mutation will fully heal your character, give you 200 bullet ammo and 20 ammo for every other type. It also fills Rogue's Portal Strike ammo. Chicken will replenish all of her lost max HP when choosing this mutation. You can also revive Chicken by picking Last Wish while she's headless inside a portal. Choosing Last Wish while holding a Cursed Weapon removes the curse. Entering the Jungle secret area will remove Last Wish from your character's mutations. You will instantly choose a mutation that replaces it, the mutations will be a completely fresh set as if you had taken patience. Last Wish will be put back into the pool of mutations you can choose from so it's possible to pick it again from this set.
Long Arms		More melee range. Melee swings will appear further from the character and travel a longer distance. Enemies directly in front of your character will still get damaged even if the swing projectile isn't in contact with them.
Lucky Shot		11.76% of kills regenerate ammo. The ammo type is equally random. It gives 32 bullets, 8 shells, 7 bolts, 6 explosives or 10 energy, which is equal to that of a Mini Ammo Chest. (the in-game text is bugged and shows less) For Fish that's 40 bullets, 10 shells, 9 bolts, 8 explosives or 13 energy.
Open Mind		An extra Ammo Chest, Weapon Chest or Radiation Canister will spawn on every level, with equal chances of appearing. Extra Chests/Canisters can appear in different forms, depending on the conditions and chances listed on the Pickups page. Chests that appear only in Secret Areas can also spawn as extras in those areas. If two Weapon Chests spawn on the same level and you leave both unopened, both will count towards spawning a Large Weapon Chest. If two Radiation Canisters spawn on the same level and you leave both unopened, they will count as one Big Radiation Canister. Playing as Rogue changes the extra Radiation Canisters into Portal Strike Ammo Canisters.
Patience		This acts as a re-roll for the current set of mutations. It doesn't do anything at first, but next time you enter a portal you will get another set of four mutations to choose from. Patience doesn't count into the mutations cap, which means you can have 9 mutations at max level (10 with Crown of Destiny). Patience actually skips to the next selection of mutations, meaning that no matter if you pick Patience or another mutation on offer, the next level-up has the same set of mutations. This only has a practical effect in seeded runs, though.
Plutonium Hunger		Increases the pick-up range for radiation, ammo and health drops (There is less of an increase on the pick-up range on ammo and health than on rads). Cursed Mini Ammo Chests are unaffected.
Rabbit Paw		(Mini Ammo Chests and Mini Medkits) drop from enemies 1.4 times as often.
Recycle Gland		Each bullet that hits an enemy or a destructible object has a 60% chance of giving you  +1 bullet type ammo back. Heavy bullets fired by Heavy Revolver and Heavy Machinegun give +2 ammo. Works only for Regular and Bouncer Bullet Weapons. Does nothing with Pop Bullet Weapons.
Rhino Skin		Adds 4 max HP. It will instantly heal your character for that 4 HP. You can also revive Chicken by choosing Rhino Skin while she's headless inside a portal.
Scarier Face		Enemies have 20% less HP. Their max HP values are reduced and rounded to the nearest full number, following the common rounding method. It doesn't affect destructible objects.
Second Stomach		Doubles the health received from Pickups. Mini Medkits give 4 HP instead of 2 HP. Medkits give 8 HP instead of 4 HP. This also affects Robot, with eaten guns giving 4 HP instead of 2 HP. Bloodlust isn't affected by this mutation. The double multiplier is added before the Crown of Haste effect. After taking the crown Mini Medkits will heal for 5 HP instead of the expected 6 HP. Stationary Medkits are unaffected by the crown and will heal for 8HP.
Sharp Teeth		Taking damage deals 2.5x the amount of HP you lost, to all enemies currently on the screen. Especially useful for self damaging characters like Rebel. Damage prevented by Boiling Veins, Strong Spirit, or taking more damage than your remaining HP will not count for the damage dealt to enemies. Fun fact, this is one of the only ways that enemies can take decimal damage.
Shotgun Shoulders		Shell Weapons projectiles bounce further and travel faster after bouncing. It causes Flame Pellets to bounce off walls, but the distance isn't as long as with regular Pellets and they can bounce off only once. Also works on Pop and Flame Pop Bullet Weapons. Normally all these weapons deal more damage up close. With this mutation their projectiles also deal that increased damage right after bouncing off walls (for two frames after bouncing, check the weapons page for the increased damage values).
Stress		Increases rate of fire in relation to the amount of missing health. The fire-rate buff provided by Stress is inversely proportional to percentage remaining of max HP. It gives you up to +100% higher rate of fire as your health gets lower. (Normal 100% + Stress's extra 100% fire rate at 0 HP) You can calculate your reload speed with (1 + (1 - (HP / Max HP))) * 100, so for example if you're at 4 / 8 HP you would have 150% reload. Rhino Skin and Crystal synergize with Stress as having higher maximum HP will allow you to smaller percentages, and simultaneously receiving more benefit while being at higher HP. Even if you have 20 max health as Crystal the highest reload speed you can have is 195% on 1 HP. The only character that can reach 200% and not die is Chicken without her head.
Strong Spirit		Lethal blows grant 5 frames (1/6 of a second) of invincibility and reduce your health to 1 instead of killing your character. Strong Spirit can activate and save your life once per area. It recharges when you leave the level that it activated in and heal back to full health. If the mutation is charged your character will have a halo above its head. Having 1 max health as Chicken or Melting will limit this mutation to save you from death only once. It can't be recharged afterwards.
Throne Butt		Upgrades your character's special ability. Fish: Roll for as long as the active button is held and can move in different directions while rolling. Crystal: Shortens the shielding time and allows Crystal to teleport at the cursor's location after her shield disappears. Eyes: Pulls enemies faster and pushes bullets away with more force. Melting: Explodes corpses/destroyed objects with three Blood Explosions instead of one. The body/object size doesn't matter. Plant: Vines kill enemies who are under 33% health. Y. V.: Upgrades Pop Pop into Brrrrap, shooting four times as many projectiles, but the reload time is 3 times as much instead of 2. Steroids: Firing one weapon has a chance to add a small amount of ammo for the other weapon. This is more likely to occur when both weapons are being fired at once. Robot: Adds additional ammo or health that is equal to one mini ammo or HP pickup when eating a weapon. Chicken: Thrown weapons pierce through targets. Rebel: Gives allies a better weapon which increases their fire rate by 60%. Horror: Horror's radiation beam gets wider twice as fast. Using the beam for extended periods of time now heals Horror (1 HP for every 1.5 seconds). Rogue: Makes Rogue's Portal Strike explosions much bigger. Skeleton: Adds a 1/3 chance that Skeleton won't take damage with Blood Gamble. Frog: Causes all toxic gas to spread further and faster.
Trigger Fingers		Each enemy killed reduces your remaining reload time on both equipped weapons by 40%. This only affects the current reload; it is not a permanent reduction. Great for the Nuke Launcher, Heavy Crossbow, Plasma Cannon or any other weapon with long reload time and high damage. The interval between swings with a melee weapon is also greatly reduced with this mutation.

Ultra Mutations table

Going over level 9 and essentially reaching level 10 (Level Ultra) allows you to choose one of the character-specific Ultra Mutations. On the experience bar the number 10 is replaced by a crown icon, indicating that your character reached its full potential. This adds 1 extra mutation to the max that your character can have. That's a total of 9 mutations, 10 with Crown of Destiny, 11 if you also picked Patience and 14 if you play as Melting with his second Ultra Mutation.

Character	Ultra Mutation	Icon	Description
Fish	Confiscate		Enemies have a 20% chance to drop an Ammo Chest (which can also be a Present Chest or an I.D.P.D. Chest) or a Medkit instead of regular mini pickups. They can also drop regular Weapon Chests instead of weapons. Not opening the Weapon Chests counts towards a Large Weapon Chest spawn. If you have a Crown, enemies can rarely drop a Cursed Chest.
	Gun Warrant		Weapons don't consume ammo for 7 seconds after exiting a level ending portal.
Crystal	Fortress		Adds 6 max HP. Crystal will instantly get healed for 6 HP. Can be stacked with Rhino Skin for a max of 20 HP.
	Juggernaut		Enables slowed movement while shielding.
Eyes	Projectile Style		While using Telekinesis, your projectiles will be frozen in a stationary position on top of Eyes, in the direction of where you shot your gun. Upon deactivating Telekinesis, all projectiles will continue to travel their initial destination and behave as normal. Melee weapons will have less range while using Telekinesis.
	Monster Style		Push away nearby enemies. Enemies will be pushed passively, with or without Telekinesis activated.
Melting	Brain Capacity		Enemies at 5 hp or less will blow up along with corpses upon using your active ability. That includes undamaged enemies.
	Detachment		Lose half of your maximum HP to immediately get 3 more mutation choices.
Plant	Trapper		6 Snare Growth vines appear instead of 1, covering a much larger area.
	Killer		Each enemy killed while snared will spawn deadly Saplings, which fly around and will home towards other enemies dealing 5 impact damage and afterwards causing 3 closely packed Blood Explosions. Each Sapling has 10 HP and can explode upon taking 10 or more damage. Each blood explosion deals 4-12 damage and destroys any projectiles in the blast radius. Blood explosions don't destroy walls and do no damage to the player.
Y.V. (Yung Venuz)	Ima Gun God		+ 40% higher rate of fire. With Y.V's passive that makes 60% higher rate of fire for all weapons (weapons have 40% of their regular reload time). It also affects how fast a weapon reloads after using Y.V's active ability. After using Pop Pop the weapon will have 80% of its regular reload time. With Throne Butt that's 120%. Sends you to Y.V's Crib.
	Back 2 Bizniz		Pop Pop will fire off 50% extra trigger pulls that won't consume ammo and won't affect the reload time. Which means a total of 3 trigger pulls with a cost of 2 and 160% of the weapon's regular reload time. With Throne Butt, Pop Pop will fire a total of 6 trigger pulls with a cost of 4 and 240% reload time. Sends you to Y.V's Crib.
Steroids	Ambidextrous		Regular Weapon Chests and Cursed Weapon Chests increase in size and drop two of the same weapons. Large Weapon Chests drop four random weapons instead of three.
	Get Loaded		Regular Ammo Chests increase in size and have 10 Mini Ammo Chests inside, giving two for each type (bullet, shell, bolt, explosive and energy).
Robot	Refined Taste		Only higher tier weapons will drop from Weapon Chests and enemies. Meaning that Robot won't find weapons which normally (without Robot's passive) start dropping from chests in area 3-1 and below (check the Weapon Chest drops table). Any weapons left behind when leaving a level will be automatically eaten.
	Regurgitate		43% chance to burp out a random stationary pickup (Ammo Chest, Weapon Chest, Medkit or a Radiation Canister) after eating a weapon. Pickups will spawn on top of Robot and instantly open. Ammo Chests have a chance to spawn as I.D.P.D. Chests. Weapon Chests can spawn as Cursed Weapon Chests if you have a Crown. Any weapons left behind when leaving a level will be automatically eaten.
Chicken	Harder to kill		Each enemy killed by Chicken adds 1 second to the time she can survive while headless. The timer won't go above 5 seconds.
	Determination		Thrown weapons teleport to your secondary weapon slot after being thrown. Weapons thrown inside a portal are not affected.
Rebel	Personal Guard		Rebel starts each level with two allies. All allies will also have 30 HP instead of 12, which in addition lengthens their lifespan.
	Riot		Every time Rebel uses her active, she spawns two allies instead of one. Each spawn will cost 2HP.
Horror	Stalker		Enemies that normally drop rads and Rad Canisters explode into radiation beam pellets upon death/when destroyed. The projectiles shoot out in all directions and otherwise act like parts of Horror's radiation beam dealing 1 damage each. Exploding doesn't reduce the amount of rads they will drop. The amount of beam pellets each enemy/Rad Canister explodes into is 60% of the amount of rads it drops. That includes radiation added from other Horror's beam pellets hitting the enemy before it dies. Enemies that don't drop rads (like the I.D.P.D. or Small Green Rats) and Destructible Objects are not affected by this mutation, unless they are hit with Horror's beam pellets.
	Anomaly		Level ending portals appear slightly before you have killed all enemies in that level. The portal opens when their combined health is equal or below 140. All remaining enemies are killed in the process.
	Meltdown		Doubles your Radiation capacity, increasing the amount of rads Horror can use for its active ability and Ultra Weapons.
Rogue	Super Portal Strike		Doubles Portal Strike ammo capacity. Portal Strike Ammo Canisters will give two ammo instead of one.
	Super Blast Armor		Upgrades Blast Armor. When Rogue gets hit, it creates four individual explosions in a triangular formation.

Character	Ultra Mutation	Icon	Description
Skeleton	Redemption		Turns Skeleton back into Melting. Every mutation you picked while playing as Skeleton will be removed. You'll be able to pick nine new ones (standard eight and one extra) and one of Melting's ultra mutations instead. Melting will have base 2 HP as opposed to Skeleton's 4 HP.
	Damnation		Firing a weapon with Blood Gamble will reduce that weapon's reload time by 80%. This only affects the current reload; it is not a permanent reduction.
Frog	Distance		Causes rads dropped by enemies and Radiation Canisters to emit toxic gas. Each Rad has a 1/3 chance to create one toxic gas cloud. Radiation Chunks are guaranteed to create 4 toxic clouds.
	Intimacy		Frog continuously spreads toxic gas as it moves. This also affects Frog's active ability, which instead of charging a big cloud of gas, will release it as you hold down the button.

 

Co-op Ultra Mutations table

Going over level 9 when playing in Co-op and essentially reaching level 10 (Level Ultra) allows you to choose an Ultra Mutation unique to Co-op which will affect both characters. You will pick it instead of the character-specific Ultra Mutations listed above, which are unavailable in Co-op.

Mutation	Description
Blood Bond	Health pickups are shared. Picking up a Mini Medkit will restore 2 HP of both players simultaneously.
Gun Bond	Ammo pickups are shared. Picking up a Mini Ammo Chest/Cursed Mini Ammo Chest will give its full amount of ammo to both players simultaneously.