Not too bad
Smooth controls and good area layouts/background. Here's a list of glitches I found:
1: 2nd stage, you can move left onto thin air under the cliff you start out on
2: 2nd stage, the razors damage you when you jump completely over them
3: 3rd stage, if you jump on the razor's left side closest to the level's start, you fall into an inescapable hole (similar problems in odd cases, check it out plz)
Otherwise, the game is pretty good!