There're dozens of options how FPS may work on 3DS: this (gyro), head-tracking (cameras) and stylus - first two are essentially the same, it doesn't matter what you move - the console or your own head - it will change point of view in the game. But those are a bit tricky to perform, while stylus though not very comfortable option but as accurate as it possibly could be. The 4th option is possible as well, which is variation of dual analog - analog plus XYAB - but 'look' and 'move' should be swapped, since 'look' requires more accurate operation through analog input (rest assured it's not a problem even for righties to use southpaw configuration). I personally would like stylus options, I passionately hate outdated dual analog setup, which is very inaccurate and hard to operate.

no, its missing buttoms.

I loved the MPH style of control, so I'll prefer it if a variation of that is used

Nope portable gaming tastes best when served with a healthy doze of turn based rpg ;)

Looks very interesting but I'm not hardcore enough to play a game like that.

I don't know why people are saying FPS don't work on DS, I loved MPH. I think the controls worked very well, especially if you're using a dslite or dsi, it can be quite comfortable since it's lighter.

Cant we just use a pen like in Metroid Prime DS? It worked perfectly there.

why not just use the joystick...

since when do FPS's not work on the DS? MPH had a great control scheme and so did MOON.