Thanks for trying it.
I only noticed the performance issues when I played the final build. It's not so bad in debug mode, so maybe it's got something to do with my test resolution being much smaller and me being really inexperienced with 3D (specifically the bad decision of adding the lights at the last moment, without realizing that lights really kill performance if I don't bake it in the textures).
My experience with the dungeon crawler genre isn't that expansive, too, since I only learned about the genre during the jam. The gameplay needs work since I do acknowledge that it's not very fun to play and really repetitive, and the theme of my game isn't in line with what a person expects with the dungeon crawler genre.
I just wanted to make a game to practice 3D.
My excuses aside, I'm sorry for wasting your time. I'll try to make a better game next time.
