Man, I have to say, the clicking particles in the speed-up button hypnotised me, lol!
I really liked being able to change the music and SFX in the settings — it made the configuration options really quirky and fun!
As others have said, I think the game is really addictive. I just wish it started a little faster though...
But I have to say, the achievement part blew me away. 33 unlockable achievements in 4 days is impressive; that can't have been easy. Congrats!