It’s The Sims crossed with Rollercoaster Tycoon with added minigames! And it isn’t very good! Well, the main game itself isn’t very good. Building coasters is great (and you’ve loads of control over the track route, heights, corner angles, etc.), but most of the minigames (in the demo at least) are dull and the graphics are really quite bad. And, for some reason, the camera just “sticks” when you’re controlling your character, meaning you sort of run off into the distance and the camera doesn’t follow. Very odd.
However! One of the minigames, Stunt Rider or something, is ACES. OK, so it’s just a clone of a Flash-based physics demo from a few years ago, but I had geleventyzwillion times more fun on that than the whole of the rest of the demo. Why not just release that as an XBLA title and not bother with the whole game, yes?