It's pretty ok, though it have some design problems - you have to do very specific things to pass the level. Very unintuive, the weirdest thing for me was that he can walk on 1-block-wide holes.
Art style is acceptable, but there could be some fixes, eg. animated lava lowered 2-3 pixels to make it feel more separate from the bricks (at the beginning I barely noticed that there was a lava pool).
Jumping sound is much too loud compared to music.
Summarizing, it's not bad, but not good either. It's old though.