Hy ! this is a very solid entry ! I encountered 2 mobs, is that what you said about the boss randomizer?
Anyway, got max upgrades, and won a lot of money with the currency bullets (by the way, in the saloon you can earn currency with these bullets !). I'm curious to see more synergies if you're planning on working on it after the jam, with bullets that have more interaction (for example, at the first i thought the skip bullet was "gain 1 additional dmg for each previous skipped bullet. Resets as soon as any bullet is fired", so I stacked two currency bullets before...until I realized that didn't work ^^"
But great entry!