That's a really nice puzzle-platformer for a couple of days! I think the bridge building mechanic in the first level alone could be used to make some pretty interesting puzzles.
It's strengths don't really lie in its platformer elements, I'd nix things like the tiny platforms in level 3. I had replay that level after falling into the water several times and the music helped keep me lucid till completion. That level's music has a very nice countermelody.