The theme is clearly well-executed here. While I’ve seen some similar ideas before, I think you stood out with the way the player controls the pentagon they’re "stuck" in.
However, I did feel a bit confused about how to play, even after going through the tutorial. Despite that, it was fun to destroy enemies and try to survive as long as possible. The particle effects gave a great sense of satisfaction when defeating enemies and bouncing off the walls.
Since the game is score-based, adding a scoreboard would be a great idea to boost replayability. Another option could be setting goals like bronze, silver, and gold trophies with predefined times (just be careful not to make them too hard haha).
The sound effects paired really well with the music and ambiance. It has a cool old-school aesthetic that definitely makes everything more attractive and immersive.
I think the only relevant suggestion I’d have for you right now would be to add power-ups for the player—like speed boosts, health recovery, or even things to hinder the enemies, like freezing them completely or partially (reducing their speed or resistance). This would significantly increase the strategic element.
Congratulations on the game, I really enjoyed it! Best of luck with the jam!