Just short of excellent
Overall, I have to say that I really enjoyed this game. It takes a while to get used to controls and what items are (you never explained in game what the bottles were), but it's a small learning curve and there's not much else that hinders the game. I did find a useful recurring glitch: Whenever I fell to a part of the screen where I would normally die, I wouldn't fall all the way off. The only way to kill myself was to hold the S button (pressing it once would have me fall down, but pop right back). The useful part is, if you move against a wall, press S a couple of times while moving towards the wall and you'll pop onto the surface (this worked even against extremely tall cliffs/walls). Some of the gems were hard to find, although I found 12 on my own somewhat easily (needed help with one in the castle and the two from the bosses). The hints were vague, but helped if you've been through that level (although it sucks that you don't get the hints until after you've collected 13 gems). The only other problem I had was that I somewhere got some really bad lag after playing the game for an hour, although a quick save and restart (closing the window) and it was gone. While this story may be over, I look forward to another similar game.