The mobile version of Trials - with a Western-style setting and mission-type level structure - is now available to download for free on iOS from the App Store.
It's the other half of a double shot of Trials goodness coming this month, with Trials Fusion releasing on consoles next week. Frontier goes the F2P route, though it does include freemium touches. A fuel tank gauge empties every time you start a level and when depleted, requires you to either pay up in real money to refill, or wait a while for it to recharge to continue playing.
We're currently roaring through the game; expect our review shortly.