Hi, thanks again for the feature. I added mouse input as a way to test touch input and make sure it doesn't break the game. I think I'll keep it in, but have you choose a control type at the beginning and not allow switching in mid-game.
I would like to add difficulty settings, if I can be a little more creative than simply adjusting bullet speed/count. One idea to help new players is a collectible hint card system for learning enemy weaknesses and more obscure mechanics. I'll have more details in my devlog hopefully soon.