I was a bit skeptical when I saw trials on the iOS store, after all, games ported from consoles are either barely resembling their counterparts or control really badly when developers try to figure out a way to make the game work at all. Trials Frontier avoids these two things, but falls down in the free to play hole pretty quickly. It’s still a fun experience for a while, controlling well and adapted to touch controls. I even thought the systems it added (leveling, loot, upgrading your bike) were better than the bare-bones progression of the PC/Console game.
That being said, all the good control schemes and interesting quest-reward systems in the world can’t save you from free-to-play systems. There’s a timer (gas) that drains when you do maps (at least you can retry an infinite number of times without taking gas, that would have been pretty stupid) and you can increase your gas capacity by spending diamonds, but ridiculously high amounts of them, instead they should’ve made it possible for players to grind it out using coins or reasonable amounts of premium-currency (that you can win randomly). But no, you can’t refill your gas forever just by playing, you need to spend money. Furthermore, after a while, races cost more than one gas, sigh.
The way the game is structured, you go to a village where people give you quests, they range from collecting items (you get a chance to spin a wheel at the end of a level to get items, and you can skew the results a bit and respin the wheel for gems) to beating certain races to performing tricks (I’ve had a terrible experience in a quest where the kid wanted me to perform 15 backflips and 15 frontflips in the same run, but apparently I could do it in multiple races? That was poorly explained) and you get money and experience for it. When you level up, your gas fills up, and that’s not entirely useful. Why not upgrade your gas capacity when you level-up, that would be actually helpful and reward leveling up!
As for the game itself, it controls fine. Your bike moves by holding down an arrow and you tilt back and forth with two other arrows. The game is forgiving enough to let you tilt a bit more than you could in Trials on PC and you can recover from some situations that would be disastrous otherwise. The levels are inventive with some one-on-one races here and there. They can be difficult as you’re not too sure if you can actually beat them with your current bike or you need to upgrade them. The computer always does the same thing so you have to retry until you get it perfectly right. I got frustrated on a level in particular where the computer managed to do a jump in a way that I couldn’t figure out how to do, so I needed to gain some time somewhere else. I’ve managed to beat that part - because I wanted to see more of trials frontier - but sadly the f2p aspect made me turn it off forever.