They ahve Defend the Tower for DS, and they even have Starcraft for DS, but they're both homebrew, and still in the making
I played one called xeno tactic homebrew tower defence game and it rocked on newgrounds, I would really like that or some other game like t the ds would be perfect for such a game, also an x-men game or an avengers game, perhaps age of apocalypse version would be sweet, a green lantern game. Mostly for me more games containing comic characters, even though I never played it the darkness on ps3 and 360 is supposed to be awesome perhaps a scaled down version for ds with different mechanics would be cool like telling the darklings what to do with simple voice commands like attack or defend touch screen implementation and maybe have a light source device like boktai that measures the amount of light where you are playing but in reverse if you are playing in total darkness except for the ds light itself you get strength bonuses.
.........I'll make a wish list ! ^^ These games aren't exiting expect Fire Emblem DS Rune Factory 4 for DS Fire Emblem DS Sakura Cardcaptor DS (it will have something to use the stylus !) Tales of Phantasia DS Fire Emblem Path of Radiance DS Golden Sun DS some more, but I can't get to remember (_ _").........