I always loved platformers, and this is no exception either. It was fun all through the levels, however the "S" button could have been explained a bit better (i thought it does teleport me down first, but I get it than in the next level, when i was on the movin platform).
Now some details:
The graphics are simple but smooth, which is good btw cause you can concentrate to the gameplay, while the background doesn't hurt your eye :)
I didn't noticed too much sounds, but which were, well, they were nice.
No violence, nor humor.
Interactivity: well, I explained that already. It was fun to play all through the game.
Style: it was a good game where I didn't feeled that "Hmm, its time to close the window soon", so the only bad thing is, that it is over too soon. So I hope to see the full version in the near future.