The game fundamentally works which is good and is not a bad attempt especially given the time limit, albeit it is a bit difficult.
Some things I feel could be worked on:
A lot of work could be done with the animations of the sprites as well as some additional animations for jumping and deaths rather than them just disappearing.
The mouse control hadn't been shown on the instructions page that it does not work, the bullets do not go as far as I feel that they should, as well as bullets going through obstacles. Enemies fire at all times at set intervals, maybe this could be adjusted so that they fire when they see you.
Bugs noticed:
Jumping randomly stops working seemingly when you walk into an obstacle.
Jumping doesn't seem to register sometimes, or perhaps it's certain locations.