Excellent puzzle platformer! Challenging, despite simple graphics, music and sound.
Level design is perfect in a sense that the player can finish the game without noticing something: Spikes/pits are the only hazard around (although the player can get stuck on places and so unable to proceed). So, as long as lessons are learned, levels become a matter of eye-hand coordination - The basic premise keeps constant: DON'T TOUCH SPIKES, DON'T FALL ON PITS.
I don't consider this game a "Hardcore" one because it wasn't frustrating enough. In fact it is much easier due to the static nature of the hazards. Although this does not disqualify the game in any way, it is implied that the author "held" a bit and didn't go all the way to make the game really, REALLY brutal.
As in, the dev refrained from adding turrets and airborne enemies to kill the player, leaving most of it as a physics platformer. Otherwise, this game could have been much harder.
What kept the game from a perfect score (5 stars) is:
1- Only one music, which gets repetitive on the way down. So, I figure most people would mute the game to listen to their own tracks.
2- Jumping on slopes (moving pieces) sometimes are bogus or just simply fail. This can get frustrating at level 30.