Alright, well that's too bad since I have an o3DS but I'll pitch my idea.
Anyways, I really miss the good ol' xevious like games. Where you are like, a ship and you "fly" along a top-down scrolling screen.
I think, it might be cool to have a new game like this, but with more upgrades and stuff. Sorta like, upgrade the game. But pixels, respectively.
Also, implementing something like how air fortress does, where it is Defender-like scrolling ship flying game, but at some points you are doing the classic ol' metroid platforming. You know what I mean?
So really, a mesh between Air Fortress, Metroid and Xevious.