Both the music and visuals are great in this game, simple but addicting to play. I couldn't get to what looks like a boss in one of the screenshots but I had some fun. Would be nice to see more species and rooms.
Something cool to add would be a stealth mechanic where all enemies don't know who the player is until one goes rogue or the player attacks. So a player constantly attacking will be swarmed quickly, but a player who's more stealthy with their kills would have the other enemies be confused and randomly attack each other from fear.