Great
I really enjoy games where your jump is limited or you can't jump at all, such as Bionic Commando. It was a challenge to beat the game, let alone collect all the gems, and rarely do you find a flash driven game where you feel like you've accomplished something solving a logic/skill puzzle. Graphics were exactly what is needed in a platform game, didn't even notice the music really so I guess that works well to create an environment for the game.
I think the one thing needed was a map, but only showing the locations you have already explored. Too many times I was running around with my new upgrade looking for a new path and ending up in the same places. Also the option for control config. some people just can't grasp the arrow key controls.
Overall a great game with perfect difficulty.