Meh
I didn't like this game much. This doesn't really compare to the other platform games out there.
The levels weren't hard. The controls are very slippery and frustrating to use. The collision detection with the rockets and hazards is also crappy. Don't write off your design mistakes as the game simply being "hard", because that is simply not the case here. The controls and collision detection work against the player, which should never, ever happen in any sort of game, even "hard" ones.
The levels lack a certain 'oomph', which made them pretty boring to go through. The tiles were pretty boring and redundant, so I'd work on that. It'd also be nice if you simply implemented some cheerful sound effect for when you beat the levels, since that really motivates people to beat the next ones. Reward your players, dammit!
This game is also very laggy on my sub-high-end computer, which should never happen in a Flash game consisting almost only of sprites. Ever hear of BitmapData? Using it helps optimize and speed up your game a lot. 8bitrocket has a tutorial on how to use it (the Atari 7800 Asteroids one), and I really recommend you read up on it and learn it before making any more sprited Flash games.