The setting and the atmosphere is nice and well done. The art is nice but I would go for constant pixel size for the whole game. The movement and jumping could use some more polis. for example: if you run up an angled platform you jump really high and if you run down hou hardly jump at all.
The splitscreen is a nice addition and the theme is fit quite well. But there could be some more gameplay elements that require both players (for example pushing big boxes)
After all a nice game with good setting.