People, stop saying handhelds can't do it. There is absolutely nothing wrong with handheld FPS as a concept. The problem is that the current set of handhelds don't have the proper set of controls FOR a FPS. The 3DS has the best one that's been developed so far, but when the NGP releases, since it will have dual analog, there will be absolutely nothing wrong with the idea of handheld FPS.
Being handheld has absolutely no inherent issues with playing a FPS. The problem is the same one the Dreamcast had, and the PS1 had before Dual Analog/DualShock released - controls.
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