This game is really cool, love that it seemingly came out of nowhere. The art isn't amazing but the animation, effects, lighting and variety sell it.
It's fun and functional just as a 2d horde survival game with its difficulty just about in the right spot, though some tweaks could be made.
Weapon & item balance is pretty off.
The MP40, PPSH, Bizon and Colt SMG do the job more than well enough at most points of progression, with the Uzi being a decent stand-by if you need more firepower early.
The MGs seem redundant - the M240 lacks the capacity, ROF, damage and reload speed for its cost, the price of its ammo and weight. The MG42 sends rounds everywhere and only just does enough damage to offset its inaccuracy, even with the recoil buff.
Shotguns are in a weird place, I find they're only useful in the earlier waves of FER but even that's a stretch. But they can kill multiple enemies with a single shot if you aim for the head and the stars align, which they do often enough. The mag-fed one is the only one I find truly worthwhile, if you can get into an elevated position.
The rifles are next to useless, and penetration (the ballistic kind, this time) is sorely needed to make them compelling whatsoever.
The pistols I haven't touched, I'm going to carry on the assumption that it's better to save the cash for a good SMG. If they replaced the starting pistol then that'd be a different story.
But these are presumably the easiest things to adjust so I'm not too worried.
My main criticism is the lack of verticality in most maps, meaning you will often have to move through the encroaching horde of enemies, and the dodge isn't quite reliable enough in most situations. I wish the player had more room to kite enemies.
A minor annoyance is that you will climb up a ledge immediately after dropping from it, if you turn to face it.
But all in all it's really fun, well-presented and well thought-out.
How do you get the headhumpers off?