Trials is a series of motocross games that takes a liberal approach to sports and, incidentally, gravity. The latest full release, Trials Fusion, saw an iOS counterpart called Trials Frontier. This slightly more cartoony take on the long-running series features the same physics-based racing and orientation gameplay - imagine it as a single-lane, dialed-up version of Excitebike. The Android version was just released, but only in certain locations. We're not sure where, we just know that it isn't the US.
In Trials, you control a motocross rider with gas, brake, and orientation, variously setting speed times, landing tricks, and landing on what used to be your face. Previous full versions managed to vary the gameplay with insanely over-the-top 2D levels and interesting bike upgrades, and those elements are certainly present in the western-themed Trials Frontier. What's also present is a time-based in-app purchase system: yeah, it's the super-annoying "energy" system, where you either wait to play that next round or pay real money to fill your fake bike with fake gas.
The 3D graphics are impressive, and so is the gameplay, but I imagine that hardcore Trials fans will quickly tire of the manipulative IAP system. Multiplayer is included, but only in the leaderboard/ghost racer style. Expect to see a wider release in a few weeks.