It's a good concept
I like the concept of this game, it sends a good message. It's also kinda fun, with a smooth interface. You might want to make it so that you don't have to click again to drop the object into the hole, which would make the game go a lot faster (higher scores too).
The only problem I have with it is that after I submitted my first score and played again, the clock went down almost three times faster. Don't know if that's a glitch, but it kind of ruined the re-playability for me. Other than those few things, you have a good 'green' game here.