There are people who recognize this as one of the best games ever made, and people who are wrong. Play Ultrakill, it will save your life.

I have a hard time comparing any game to this. It's my favorite game of all time, without question. Nier Automata comes close, but this was just a one of a kind journey unlike any other. Having beaten it on PS4 I was more than ready to play through again on PC. Truly the worst part about this game was that I would never be able to experience it for my first time again.
This game gets it all right. It has a message and it delivers it flawlessly. The entire game is structured around an idea, and this core vision is what lots of games lack and keep them from truly becoming masterpieces.

Oh, and if you're looking for the game's intended difficulty, play on the new Very Hard! It's weird saying this given it wasn't in the game at launch, but even on hard the game's combat is not meant to be it's highlight. I'd argue this game is very in line with that of the survival horror genre. Your resource management and dealing with just getting from point A to point B is the real enemy. So if you consider yourself good at video games and want the game to be truly satisfying, play on very hard!