This is one of those games where I think it was done well but I just didn't like it all that much*. I'm not personally a fan of games where the only objective is score. I like my shooters simple; with constant spawns, the floor changing color, being able to fall off the map, and some enemies actually friendly there was just too much going on at once for me.
I don't know if it was actually happening or just seemed to be happening, but I thought some enemies were changing from green (friendly) to red (evil). After a while I gave up on trying to get a high score and just killed everything that might be a threat.
I think you gave the retro theme a good shot, but it just doesn't feel right to me. The biggest problem is that I'm not sure which period you're going for. The HUD tries to be 8-bit (although the drop shadow kinda breaks the illusion), the weapon sprites are mid 90s, and the 3D enemies and environments are late 90s-early 2000s. The company logo/intro is firmly New Tens and the main menu is mid-late 2000s.
I'm also not sure what's up with the streamer in the corner. I feel like it's a joke that I almost, but don't quite, get.
It's really, really hard for me to rate this one. I think it actually is a strong entry, but it didn't really click for me.
* You stand in good company at least; I put Undertale, The Witcher 3, and GTA V in this category.