It's not a technological problem, it's a hardware problem (at least from my non-visionary point of view). Twin thumbsticks are required. Anything else and it's a recipe for frustration.
Metroid Hunters on NDS was probably the best I've personally seen, but it's the best of a poor breed.
The Vita is the first mainstream handheld with twin thumbsticks, but IMO Sony has an extremely hard uphill battle with their device. Portable gaming is moving away from handheld consoles. I would love to see it happen, but I personally doubt we'll see a Quake-level success on the Vita.
Metroid Hunters on NDS was probably the best I've personally seen, but it's the best of a poor breed.
The Vita is the first mainstream handheld with twin thumbsticks, but IMO Sony has an extremely hard uphill battle with their device. Portable gaming is moving away from handheld consoles. I would love to see it happen, but I personally doubt we'll see a Quake-level success on the Vita.