Everything looks good, and the world is quite dynamic.
Audio would have really rounded out the presentation. I always feel like a little bit of effort in this department goes a long way--some free to use tunes, a few old-school sound effects from bfxr, and the game world feels much more alive.
After respawning, I often experienced a bug where the character would turn sideways, and I couldn't get him right side up again. Screenshot below.
Did you forget to constrain the Rigidbody2d on the Z axis? That might be the problem. ;-)
