Personally, I am not too fond of this mutation. Perhaps it was because I played it on Expert, but it just feels like lousy RNG can end any run, and it's not particularly fun to play due to how slow it is. I feel like the "All Alone" mutation does what this mutation tries to do but in a way that's more enjoyable to play through.

Some other points:

1. Tanks are very easy run enders. They move faster than you, and without a Molotov, you're pretty much screwed unless you get lucky with the tank grabbing onto objects. If a tank spawns ahead of you after a horde spawns or if you just happened to have a couple of zombies behind you, your run is over.

2. Crescendo events suck. You WILL run out of ammo, and then you will get mobbed by a horde of infected you can't cut down.

3. Melee weapons are useless without landing headshots. They sometimes don't kill even with TWO swings, and if you don't kill whatever's hitting you in one swing, you will 100% get hit. The unreliability of melee weapons makes Deagle the superior option in every scenario.

4. Grenade Launcher blast radius seems to be smaller. Also, the shove is terrible, so if you go with the grenade launcher and get bad rng with infected blocking the way, that can also end any given run since your reload and shove are so slow, which makes the Grenade Launcher not very good to use. Unfortunately, the Shotgun is not great either because it can't clear groups of infected when you get low on ammo.

5. Being able to take your time would mitigate most of the listed issues. Unfortunately, random hordes are still a thing, and if you aren't constantly moving, they can spawn right behind you, and you're screwed. They can also spawn AHEAD of you, and if you don't have the grenade launcher, you might as well let them kill you.

This mutation is probably less frustrating on lower difficulties, but it is poorly balanced for Expert. Aside from that, the reduced movement/shove speed just kind of ruins the flow of the game. Here's hoping that you continue to improve the mutation in the future, but I think perhaps it's just not for me.

This is a discussion post and not a comment because it's too long to post in a single comment.