Great theme matching! Its the strongest point. The weakest point is the GUI, which looks like it was an afterthought which is a huge problem since its looks like you were going for a rogue-lite / shop mechanic. In the future I recommend making the GUI and menu layouts before anything else. It allows you to set up a winnable state which this game does not have (making it an incomplete game in my opinion).
While the game had some good sound fx, not having any music makes the game boring and lifeless (in a bad way). I get that's goes with the theme of a Wall-e world, died and boring, but at least having some ambiance music is considerably better than nothing.