Gorgeous graphics, smooth controls, physics feels right, nice level of difficulty.
I don't like the way the ship auto-docks when you get near the landing point. I'd prefer it if you had to (carefully!) land manually, which was one of the best things about classic "lander" games. Though would be frustrating after a tricky level.
A lot of the levels you can win by being super-cautious and not worrying at all about the clock. Unless you're speedrunning or playing with a friend, the clock doesn't make any difference. Having bronze/silver/gold medals for each level, based on time taken, would have made the clock a more important element of the gameplay and increased the replayability?