Mad Skills BMX (iOS - Universal) is the spiritual sequel to one of my favorite games from a couple of years ago, Mad Skills Motocross. The game is similar to the original (and as addictive), but a different control scheme, new challenges, and upgraded graphics put this version in a league all its own.
The graphics in Mad Skills BMX are a huge step up over the original. A closer viewpoint brings the bikes into greater detail and a sort of cel-shaded art scheme gives the racers and tracks a cartoonish but detailed look.
The folks at developer Turborilla recognize that the technique involved in riding a real BMX bike is quite different than that of motocross, and the game accounts for the differences with a new control scheme. You touch the left side of the screen to pedal, but it's the swipes and gestures on the right side that take the most mastery and make the game interesting.
On the first tutorial level, the game will show you with onscreen graphics how to perform the different moves. A swipe down and hold rushes your bike downward so you can get the most out of down slopes in the racetrack, but it also makes your racer perform wheelies -- the fastest way to race through what the game calls "whoops" (rolling jumps). A swipe up makes your racer jump.
A swipe and hold to the left or right while in the air performs a flip. Flips are a great way to get a little extra boost, because they give you 4 seconds of fast-pedaling adrenaline. For each of these moves, it's hard to master the timing to get the most speed out of every track, so expect a difficult learning curve in the beginning. Actually, expect a difficult learning curve the further you go -- this game is not easy.