Playability:
Simple and straight forward design. Getting some performance issues which means something is a bit too aggressive checks-wise somewhere. You made the box move and that's what matters most! Nice work!
Theme:
Light implementation of the theme by going a stealth gameplay route. Nothing negative here but would love to see more.
Cleverness:
Simple for now and that's ok. It's your first game so remember that!
Artistic Style:
Simple and consistent. Programmer art is a rite of passage.