Here's Xeodrifter, a new game from the Nintendo-friendly indie studio Renegade Kid, who are perhaps best known for the DS shooter Moon and the platformer Mutant Mudds.
Lots of retro-styled platformers can be found in the Games section of Apple's App Store. Most of them play like crap. Developers can ape the look and sound of old-school jump-and-shoot games, but that amounts to nothing if control doesn't feel right.
Another horror FPS on DS? All too rare.