The best way I can describe it is "decent." It's not as amazing as the hypsters made it out to be, it's not as horrid as some will make it out to be.
Control, in a lot of respects, is similar to Skate in concept, but in practice, not near as responsive. The design of the mountain is pretty good- always something to jump off of or jib. Decent variety, and the art direction is rooted in reality.
Graphically, it's geared more to the macro than the micro. Draw distances are amazing, but some of the textures look rugged up close. But considering that most of the gameplay is zoomed out, it's fine.
Biggest problem is the progression. Having all four mountains (five if you get the Target edition) is a blessing and a curse. It's cool to be able to do what you want, when you want, but there's little motivation to start knocking out challenges.
All and all, I'd say it's a great starting off point. It's worth a rent, for sure, and I'll give it an A for effort, but here's hoping that the sequel is better.