Love the grass. As Somebody said, it's looking a lot like limbo.. just bright and happy. Can't wait to see how you put your own spin into it though, the physics puzzles look like they could get interesting with all the interactions in it so far.
I think the main 'Limbo-likeness' would be the character's pulling animation, perhaps if/when you add more character to the protagonist you could give him a funny strained expression or something to set him apart?
Bravo and cant wait to see it finished ;P