This game is neat!
The art is amazing, the Book upgrades bit was super cool and gave me so many options to choose from which was an interesting way of showing balance.
The sounds matched up perfectly with the gameplay and the tune at the start screen was very good. The only let down was within the gameplay.
The main gameplay of shooting and moving feels very good and responsive but once you run out of bullets it seems impossible to collect anymore. In my multiple runs of the game i never got a single bit of ammo so the moment i ran out of bullets i was unable to play any further which is sad because i was really enjoying it til i reached that point.
I tried giving myself more ammo to see if maybe it was a time thing or enemies killed thing but still no ammo. Typically in these sorts of games the only guns with an ammo count are upgrades and theirs always a secondary to fall back on with infinite ammo or the base gun is always infinite ammo and the upgrades would be chosen at the start as yours does
Furthermore another problem i encountered was that once you die it tells you your score and your highscore but under that is just a blank space and no options to back out of the menu, so effectively everytime i die on the game im forced to close and reload the game so i can play it again, which again is a shame.
Overall you have a very good game their however those two major issues are a huge issue that i feel breaks the game almost entirely which is sad because had those issues not been present i may have said that was one of if not the best game i had played from the jam.