When I say zelda-like, I mean because of the top-down view, the way you get new items. (both metroid and zelda have that item thing going on)
For the lock fire thing, at least in my experience, it's what made later levels harder than they actually were. I kept shooting in the wrong direction because with my habit of shooting, i'd start shooting before turning (or close enough for it to be considered done first) making it terrible when I try to turn to attack an enemy (i lost a lot of health because of it); might depend on the players habit, but at least we know one person who was affected by this :p
About the hitbox, it's true that it's kind of unavoidable with such a resolution... I was thinking about making the bullets have a different hitbox (smaller when enemy, bigger when player) but due to the resolution, it might be difficult. But yeah I guess having an hitbox for registering hits from bullets could also be an option (but with the time frame of the jam, maybe it isn't that easy)
Gotta say for the Boss though, aside from him being too fast, it did feel like a good boss fight.
Ah I see, too bad for the weapon cooldown, I did hope while playing to upgrade it; it's a nice thing that the weapon got upgraded in power though! (though it would have been nice to have an upgrade in power sooner to feel a bit more powerful against some enemies; perhaps between the final power and the initial)
As for the font, I myself used pixelated. It's a bit big, but it's the smallest I found that seemed readable.