I also found this game to be intensely beautiful. It’s a 2D side-scroller, but the visual depth is such that it’s easy to forget that you’re locked in. The music and art, combined with the fluidity of the game mechanics, consistently impressed me.
The only very minor disappointment was the puzzles. Trine combines a 2D platform side-scroller with a puzzle game, which works very well, for a while. After about 3/4 of the way through, though, the puzzles start to feel a bit repetitive. There were a few that were pretty challenging, but by the end they started to feel pretty easy. This was only a minor frustration though, as most of the puzzles were very fun.
Overall, I found Trine immersive and fun, and I would highly recommend giving this game a try.