A complete little game, perfect for a game jam.
The art, the preview feature, and the writing in the water give the game a really polished feel (did you work the full 2 weeks on this?!).
:)
A reset button would be nice; but you already know that, and most of the games don't seem to have one.
Aside from that the only improvement I can suggest is adding more levels.
Since you must empty the hub, you can do all sort of combinations of different amounts of objects to (hopefully) keep it feeling fresh for a bit longer.
Can we fit 20 trees on there, for example?
You could also add a couple easier tutorial-style levels where the turtle doesn't get so full.