Good Game!
Choosing to make an IDLE game is risky bet, but it definlty works for me here! We really got the satifactory feeling from reaching a new miletone, witch is everything is this type of game. I do think you could enphesis it even more using more particules comming from the monster whenever you killed it. Sound design is okay, and overall the game is quite polish. I do enjoy “”“collecting””” every monsters faces there are.
A way to make it even more enjoyuable was maybe using more kind of powerups, maybe some one-off one that you can use on certains types of nightmare, so it’s not a fully passive game.
GG!