I really like the vibe of this game, very "retro". The song is banging and the visual effects are really well made, but I fell they could be tonned down a little bit in size/number of particles.
2 things about the gameplay, dying could punish the player, on my second go I tried to reach the boss without firing a single bullet and was able to do it, died multiple times and it didn't really matter. And you can also get "under" the boss and never get hit by any projectile making it very easy to kill.
But the game is very fun, good job!