Darken the background so that it doesn't blend with the foreground. Also, while editing(I tried, but I didn't accomplish anything worth posting), I noticed that you use a lot of colors for your sprite that are in the background... that's the major problem. How do you expect your sprite to stand out from the background when it actually uses most of the same colors?
Perhaps change his shirt to blue, or camo(green and brown, with some light brown), or anything not brown.
edit: this is concerning the last one everyone is talking about.