Really cool game to play. Here I'll leave a feedback on some on implementation.
I played the game 2-3 time and noticed everything was pre-placed even the upgrade items, for the Jam I think is ok, but still think adding a little more random would make it more fun to play, also I feel items should be dropped by the enemy ship.
The wave form bullet was not been destroyed on hit, so I thought I was not doing damage to boss at the end, There was no way of me knowing if I was hitting since there was no hit sound effect either.
Overall very good game! Congrats on your entry!