I'm thinking of a few more bosses and some temporary buffs like crazy fast shooting or temporary invulnerability and stuff like that, and I'll probably add a title screen and make an actual end level so the game is beatable, but overall it's gonna stay simple

Just looked at your game I'm a bit confused on what I'm doing but I like the visuals, do the areas open up when numbers match?

when you're near blocks that can be mined youll start doing POW. When the number matches (turns green) you can clear it with O. Different types of blocks have different effects or functions. Collect 3 crystals and you can kill an adjacent Oni with the X button