The levels are pretty boring. Nothing going on. And why are all the walls angled? To me it makes more sense for a modern tileset to use straight lines because thats what you would see IRL. A little boring but more realistic.
Try making some outside levels with the default tileset (Pic2.png) or the iClassic tileset (Can be found in the sticky). I would love to see what you can come up with, as those tilesets allow for a LOT more creativity.