I enjoyed reading the comments but I feel lengthy off topic discussion should be performed in a corner.
@Nolonar: about game-pad - PC supports analog game-pad, thus your argument is invalid.
To those considering FPS in smart phone is lame, kindly try Guardian Cross (available in Apple and Android).
To aim you use your left thumb or gyroscope. To shoot you use your right thumb.
I was terrible at arcade version of House of the Dead. On the other hand I performed much better in Windows version (aiming with mouse).
Yet this fact didn't give me satisfaction, quite the contrary I felt kinda lame (no offence intended for FPS players worldwide).
Yes, aiming with mouse is faster and more precise, but it's far from the real thing.
To prevent tl;dr I'll stop here.