I adore these games, and PastelGames all together. I had to send some kreds. Also, I never had an issue with inventory space, but I didn't gather everything and then do the quest things. Try to do a few things as you get the items. It cuts down on the space needed.
Alright, I kinda see where you're going with this, reminds me of Guitar Hero or rock band a little, in the way you have to match the beat/mark. Add some nice graphics and maybe a way you can take on more patients or something.