Music-themed game. Not a rhythm game, but just music themed. it would be like an online/multiplayer thing, where you could have an instrument and use notes to attack other people. there could be different modes, like duet(2 on 2) trio(3 on 3) or an orchestra (10 on 10). every attack, there would be like the slider thing from undertale that you have to time it to deal more damage. whichever team wins would be based on how accurate your notes were, and how many ko's each team got. the audience would then throw money at you depending on your personal score. you could upgrade your character's base stats, as well as their instrument stats. as you play more battles you earn xp, which can unlock new instruments. you could also spend money gained in battle for cosmetics and character and instrument upgrades. there would also be a single player mode, where you can unlock special upgrades and instruments used in multiplayer battles.