I like the artstyle and I appreciate that you got SFX and some atmospheric background music in, which do add a lot to the general feel of the game. It seems like a lot of work has been done within a short time, so you've done well.
I will say that I found the black 2.5D level boundaries to be confusing and often found it hard to judge the exact height/distance of steps/platforms against the play. Maybe if the parallax effect was reduced a bit it wouldn't be so confusing? or maybe introduce shades of black->grey on different surfaces to make them distinct.