The shooting of this game is just perfect: the player has a good feedback through sfx and particle effects, and the enemies are not too op or weak. The moving enemies AI is the thing I liked the most about this game. They try to predict where the player is gonna shoot and that makes the game even more challenging.
The background, the audio, and the "fog" effect when the player is moving give the right atmosphere to the game, so well done on that. Just want to give you three tips:
1) sometimes it's difficult to see where the bullets go (except for the second ship) and where the enemy ships are (especially when the background is bright). Maybe you want to highlight more the bullets by making more big and bright (maybe with a trail or something) or maybe you just want to make the background a bit more neutral.
2) when the player enters a planet, the enemies should enter in a pause state, not going towards the player and shooting to him.
3) remove the ui from the game icon!
In the end, you managed to keep me entertained for 40 minutes and considering the average time I play a game of a jam is 5 minutes, that's a pretty good result! This game also reminds me of a game I used to play when I was a child called HellFighter32