So very... bland. you need to explore the different configuration of the tiles together and come up with something more exciting. Yeah, the tileset sucks, but so does your light effects (which by the way, are off by +.1/.2x).
Anyway, if you want while effects, the level needs a darker hue, then it would go just perfect. Mabey add a bit more to the level, but dont crowd it because then it looks worse.
And well, I don't rate levels, I give advice.