Good, but could be better
I agree mostly with apenguin09 here. You add a twist where you can turn off gravity and friction, etc, but you did give a bit too much control to the user. I like your idea, but to much control is given to the user, esp. with the green blocks. You should maybe have areas that don't allow clicking, or add more interesting things, like a timer, to the level.
At least it isn't new people who dump their crap onto the actual main page and not the dumping grounds.
I didn't actually do that, I just forgot to tell people I was new and had little experience.