Killing floor 2. It's a great game, and I love it, but it has downgraded in every way since mid-early access. It's too bright now, they ruined the flashlight system, made it way too easy, and added some really stupid, annoying enemy types.
That said, I just can't get enough of it. After all the bad decisions they made, the core experience is so good that it's still a solid 8.5/10 for me.
KF1 was such a blast so many hours grinding every level 6, modding servers, to me all they had to do was give that game better textures and polish some things and I would be hooked again, kf2 missed the mark for me.