I have a strong memory of getting madder while playing Trials Evolution than I ever did at any game before or since. It wasn't Trials specifically I was mad at, it was me. I'd been trying to land some ridiculous jump thirty or forty (or more) times, failing, and tapping the button to load the last checkpoint every time I missed the jump. And when I finally landed perfectly, but before I'd crossed the next checkpoint, I reflexively hit the load last checkpoint button again. I'd finally made it, but now I had to do it again. After all those failures, I'd instantly erased my long-fought-for success.
My point is, Trials can make you mad sometimes, but with Trials Rising, coming next year, it could make you mad at someone else for a change. I got some hands-on time with a work-in-progress demo of Trials Rising at E3, and along with the crazy courses, explosions and wrecking balls, and high-flying and far-flinging action, it's bringing along a local co-op mode.
(Quick note: the gifs included here don't accurately show the quality of the game. The framerates during the demo were great, I'm just making gifs on a somewhat aging laptop that struggles when I try to play video footage on it.)
Two players. Two seats. Two sets of handlebars. But only one bike. You and your co-op buddy ride together, jump together, and hilariously wipe out together. As with solo Trials, you lean forward and backward to control your jumps, you give the bike gas and hit the brakes. But now you have to do it with your partner, in unison, in sync, or you're both going to wind up with a total of 412 broken bones.
If you fly off a ramp and you lean forward to do a front flip, but your buddy leans backwards to do a backflip, you're gonna cancel each other out. Then again, if you both lean forward or backward at the same time, you might do a couple more revolutions than planned. Give it gas at the same time, and the bike will gain extra acceleration, which is great unless you speed a little faster than the next jump requires. In unison, two riders can pull off amazing stunts. Get your wires crossed and it's like a mid-air wrestling match followed by thirty seconds of ragdolling.
This is a hell of a lot of fun, by the way. I had a great time playing Trials in co-op. But if you and your friend have tried to land the same jump thirty or forty (or more) times, and someone accidentally blows it, instead of getting mad at yourself, you'll be able to turn to your buddy and get mad at him instead.