NBA 2K13 for iOS isn't going to impress any owners of the console versions (which most agree are excellent), but it's still a passable arcade basketball game with great-looking graphics on your iPhone. Before you rush out and pay the price to download it, though, I can't recommend the game at the current price mainly because of the controls. Also, though I tested on iOS, you can get NBA 2K13 for Android here.
The control system is not very complex; although that's a good thing for a touch screen, it's not as good for playing a 5-on-5 basketball game. You get a control stick on the left for moving your players, and pass and shoot buttons on the right. The game also comes with single-finger touch controls, but it's mostly a passive playing experience where you set loose strategies while controlling little actual movement. As a longtime fan of the series on consoles, I chose the more classic approach. To pass, you need to point toward another player on your team with the control stick, then hit the pass button. Unfortunately, with this setup you'll end up passing to the wrong player frequently, which gets frustrating. There's no juke button, either, but the game will let you do crossover moves with a quick back-and-forth on the control stick. The problem is that the juke move is not as responsive as I would like, so I often got frustrated trying to spin around another player.
Shooting only requires touching and holding the shoot button, then letting go at the top of your player's jump. In my testing in the Quick Game mode, shots seemed to go down pretty consistently (for both teams) as long as the player created a little space between him and the defender. Overall, the control system is mostly adequate for arcade basketball, but it's not as realistic as the console versions and quite a bit more frustrating.
The best thing about NBA 2K13 for iOS is the graphics, though there are issues here, too. Courts are crisp and look great, player faces are mostly recognizable, and the animations look great as you're playing. But even on my iPhone 5, which you would assume to be the optimal device for the game, there were significant hiccups and lag while I was playing. It's also important to point out that as of this writing the game does not use the whole iPhone 5 screen, but I'm noticing this is pretty common in the early days of the device while developers catch up.
Discuss NBA 2K13