Mutations - The Good, the Bad, and the Scary

Hello, and welcome to a guide on mutations. I figured it would be important to have a few tips for new players, so here we are. I am a believer that having good mutation RNG is one of the most important factors to having a fast run, maybe even more important than good weapon RNG. With that in mind, I want to analyze each mutation and determine how useful it would be in a speedrun. This will be in alphabetical order, and each mutation will be given a rating from 1-5. 

To get a better idea of this rating scale

1.  Worthless in almost every scenario. The proper utilization of this mutation will most likely cost you time.

2.  Only helps slightly, and should probably be ignored as well. 

3.  Usable. It is a definite benefit to your run, but there is still probably better. If you get this on your first level in a 1 Character run, I would probably reset unless I have some really good weapons.

3.5.  Patience tier. I believe Patience is a very important mutation, and I'm sure most of you will find yourselves taking it very often. Essentially, if you have anything at 4 or higher, take that instead of Patience. If you only have mutations that are 3 and lower, go for Patience and hope for the best.

4.  I mean, what can I say. They are really good. The make you win fast. 

5.  The best of the best. Essential for any speedrun. They make you win faster.

So lets get started.

Back Muscle - 2
So many people love this mutation when playing to loop. Having a huge stockpile of ammo is essential for lasting as long as possible, but that is not our goal here. Picking this up early can usually lead to you having an ammo supply higher than your previous maximum capacity, but that will generally be depleted fairly quickly, making it dead weight for what could be a much faster run if another mutation was taken instead.

Bloodlust - 2
Bloodlust offers us a decent amount of survivability, but at the cost of an uncontrollable negative synergy with Stress. It doesn't really make you win any faster, so it is essentially a waste of a slot.

Boiling Veins - 3
Personally, I despise using explosive weapons. While explosions are great for killing large groups of weak enemies and can still kill a single high hp target without much trouble, the fact that they cannot kill anything at close range without killing you is a huge downside. Not only will this mutation allow you to hit things at close range, but it saves you from things like car explosions, those suicide bombers in the labs, and it allows you to essentially stand on top of the throne when it explodes, cutting a second or two from your time. Unfortunately, in the grand scheme of things,this doesn't really help much to make your run faster, just safer, so it only gets a 3.

Bolt Marrow - 3 (5 if you have a bolt weapon)
So here's the deal. Generally speaking, it is not worth the risk of taking this mutation without a weapon that benefits from it. However, when you do have a bolt weapon, this kicks ass. The ability to kill a room full of weak guys with 1 shot is insane. This is essential for any run that is using a bolt weapon. Also not that great with disc guns.

Eagle Eyes - 2 (5 if you get the right weapon)
So, there are scenarios that make Eagle Eyes the best mutation in the game, and many more scenarios that make it useless. If you manage to pick up something with a huge shot spread like a triple machine gun or a minigun, this ends up being a disgusting combo. So the question is, is it worth it? Probably not.

Euphoria - 2 (3 with Eyes)
The only person who actually shoots fast enough for it to be a concern is Lil' Hunter, and even then it doesn't help much with that fight. When combined with Eyes, it does become more useful, but there are still plenty of other things I would take over this mutation, even as Eyes.

Extra Feet - 5
C'mon guys, it's a speedrun. This gives you more speed, pretty easy pick here. In all honesty though, this is probably the 2nd best mutation in the entire game for speedrunning. It cuts a bunch of your time from your run, and it negates spider webs in the caves, which is very important.

Gamma Guts - 2?
I will admit, Gamma Guts is weird. I don't think I have ever actually taken this mutation in a speedrun before, because it just doesn't seem very beneficial. I guess it can help you clear the labs faster by just running through the freaks, but even then, how useful is that?

Hammerhead - 1
So yeah, Hammerhead is probably my least favorite mutation for speedrunning. I understand it can give you the ability to make shortcuts between different areas of a map, but is it really worth it? The one thing that this mutation was designed for was to dig out a small area in a wall and camp out the enemies by bottle-necking them into your entrance. That takes waaaaaay too much time. And it has the added bonus of constantly accidentally breaking walls you are trying to take cover behind. It just does so little to help you, and I hate it.

Heavy Heart - 3
So, Heavy heart is hopefully a mutation you should never have to see, due to the fact that you need 3 weapon specific mutations in order to have it show up. If that is the case, then I suspect that your run isn't going so well. That being said, extra weapon drops is never a bad thing. Worst case scenario, they give you more ammo. Best case scenario, you get a crazy good weapon. It has the potential to win a run, but also to do nothing.

Impact Wrists - 3
While this isn't the greatest dps buff, it is still technically a dps buff, which will make you go faster. That's all I can really say about it since there are certainly more important mutations to take. The fact that it doesn't help you very much with boss fights is the real reason why this doesn't get a higher score.

Laser Brain - 3 (5 with laser weapons, 4 with lightning weapons)
Similar to Bolt Marrow, I would generally prefer not to take Laser Brain unless I already have a weapon that benefits from it. It definitely helps laser weapons become endgame powerhouses, but it doesn't do as much for lighting weapons. Still can be a very strong mutation.

Last Wish - 2-4 Depending on Situation
A lot of people give last wish a ton of shit for being terrible, and it isn't that good. However, in the right situation, this can be a very good mutation. That situation is having very little health, not having Stress, and being low on ammo. That combination makes last wish very good, which should seem pretty obvious. If any of those conditions aren't met, then it sucks.

Long Arms - 1
I don't like melee when speedrunning. All of the early game melee weapons are bad, and banking on getting a better one late game is not a great plan. Even with a good melee weapon, the increased range doesn't even help that much with your run.

Lucky Shot - 1
The best of the worse in my opinion. It is really only usable early game, and even then it sucks. The ideal scenario is that you get this early, progress through the entire game collecting ammo for guns you aren't using, then at the end get a gun that can actually use this stockpile of ammo. If you get it mid game and beyond, it basically will end up giving you nothing. Don't take this.

Open Mind - 3
So there is definitely an argument for why Open Mind is bad, and that argument is that in order to get the benefit from open mind, you have to go out of your way to open the extra chests you get, slowing you down. While this is entirely true, on of the things that I enjoy about this mutation is the extra weapon chests that spawn from it. Now that same argument can be made as a counterpoint to my previous statement, but the benefit if having more weapon chests isn't opening them. The whole point of having more weapon chests is ignoring them so that you can get big chests in the late game. Having more endgame weapons drop can be a huge advantage. The only reason that this gets a three is that you don't really get anything out of it in the early-mid game sections.

Patience - 3.5
Read above in the 3.5 tier explanation.

Plutonium Hunger - 3
I feel like people seem to enjoy this more than they should. While it does help you collect ammo and rads faster, the extra range it gives you to pick these up never really seems that important to me. Whenever I take it, it just feels very bland.

Rabbit Paw - 3 (4 if using laser or bullet weapons)
Extra drops are very seldom a bad thing. One of the huge differences between this and bloodlust is that the health you gain from this can be ignored if you are using Stress to increase your rate of fire. Weapons that burn through ammo need this more than others, but it still isn't necessarily essential.

Recycle Gland - 3 (5 if using bullet weapons)
Similar to the previous weapon specific mutations, this on really only benefits from having the specified weapon. That being said, this along with a minigun can single handedly win you an entire run, so don't count it out.

Rhino Skin - 2 (5 for Melting)
Very boring. Doesn't help you do anything faster. Has a tiny synergy with Stress, but really not worth much in the long run.

Scarier Face - 5
This is literally the best mutation in the game. In no scenario should you take anything over this ever. It turns 3 shots into 2 shots, it makes all bosses 20% faster, and it makes you use less ammo to kill things. Pretty simple stuff there.

Second Stomach - 1
Another mutation that only gives you health. The reason that I rate this one so low is due to the negative synergy it has with Stress. When I use Stress, I usually try to float around 3 health. If I take second stomach and accidentally pick up a health pack, I have now lost almost all of my bonus fire rate. At least with Bloodlust, it is easier to maintain having a low hp amount with it.

Sharp Teeth - 1
This may be the worst mutation in the entire game. Some may argue that it works well with something like Stress, but the entire point of stress is maintaining a low amount of HP and staying there. Once that has been done Sharp Teeth goes back to being useless. And even the amount of damage it deals is practically worthless as well. It sucks.

Shotgun Shoulders - 1 (3 with a shotgun)
The benefit of shotguns being able to bounce off walls is often irrelevant, but when it is relevant, it usually does a nice job. That being said, this mutation is not very good.

Stress - 5 (3 for Melting)
If you want a fast run, sometimes you gotta live life on the edge. This is by far the scariest mutation to use effectively, but is key to a successful run. The increase you get from having low health far outweighs the risk of dying. Even with half health, you get a passive 40% fire rate increase, which is insane. Just make sure you don't waste all of your ammo.

Strong Spirit - 3 (4 with Stress)
The reason why I believe Strong Spirit is better than Rhino Skin is because Strong Spirit saves you from all those nasty insta-kills, and has a stronger synergy with Stress. When you accidentally collide with a laser crystal, Rhino Skin won't save you. Even with the recent nerf to it, I still prefer it over Rhino skin.

Throne Butt - ???
So since throne butt is character unique, it's value varies based on who you are playing. I will say that Steroids, Y.V, and Plant probably have the best ones, but even then, they would only be a 4.

Trigger Fingers - 4 (2 if using an fast automatic weapon.)
Pretty simple stuff. Great if you have a weapon with a long reload that kills a bunch of stuff in one shot like crossbows and explosive weapons. Terrible if you have a minigun. Ok in most other scenarios.



And there is my guide on mutations. I hope you find it useful.

Cranberry

Nuclear Throne

Wonderis_

dngs

krispinesss

pateson

Mythomagic

Fish

Crystal

Eyes

Melting

Plant

Y.V.

Steroids

Robot

Chicken

Rebel

Horror

Rogue

Skeleton

Frog

Any%

All Areas

Captain

2 players

3 players

4 players

All Bosses

Char

P1 Character

P2 Character

# of players

P3 Character

P4 Character

March 19th 2026 Leaderboard Update

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PSA: Regarding Update 100 & Bugs

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