This is an interesting game, and some really tricky puzzles. I wish there was some sound or music, and also it would be nice if the game could somehow force you into putting barrels into valid positions (like not let you walk so far it would go into the wall), or automatically reset when you get trapped, but at least you have the reset button there.
Like I said the stacking mechanics really lead to some interesting puzzles so I think you could have something here, with a little more refinement