OOO I love that!
I remember playing a game like this at the arcades, can't remember the name but I love how you add on that with the grabbing of the points with the little cart, it adds a whole new dimension, found myself constantly shifting my eye from the color to what was dropping and it actually was a challenge. One small thing is that early on in the game from stages 1-4 you can just shake your mouse from side to side really really fast and it would catch all the falling things no matter how many there were. Doesn't really work further on but still maybe you should change the speed he moves.