I would love for a mecha type character to appear in a Touhou game (Utsuho doesn't count, besides, she's not a robot). Just seeing the mecha (having a girl voice) shoot giant lazers and missiles that explode into lazers, that would be cool! 

Better yet, a touhou fighting game where the characters pilot a mech and fight each other in it 

Ok this is like gundam. WE NEED MECHA TOUHOU TO BE A REAL GAME