Likes:
Full-screen mode was nice (it would have been too small a window to play otherwise).
Large sprites made it easy to see what was happening.
Medal-system was a good bonus to also having a scoring system. I think I got 3 medals. My high score was 467 after getting to level 5.
It definitely has that 80s feel to it.
I liked how on the credits page you even included the link to your source material.
Improvements:
Sometimes the enemy would just sit there and not even shoot at me.
Firing one bullet at a time gets a little boring after a while.