Hey Psynut, thank you for the kind compliment!
I decided to try out a unique weapon system for my game rather than the tired & true 1, 2, 3 weapon mapping and reloading one might normally expect from the genre. As your arsenal here consists entirely of Energy Weapons, they need a moment to recharge after being used, and they do that while sitting inactive in your inventory. Meanwhile, you automatically rotate through the others. Upgrading your gun does increase Maximum Ammo as well as set the Ammo/Energy back to Maximum, as you may have noticed, allowing you to favor a gun somewhat over the others.
It's a system that probably needs some tweaking to feel just right and allow players to choose their favorite "Ringer", but I considered a game jam the right place to experiment with something perhaps innovative like this. I personally don't love the obsessiveness of reloading after every couple bullets fired and I really dislike running out of Ammo in games like this, plus I'd like to encourage players to use all their weapons at least a little rather than just rely on one faithful standby, so I was thinking about ways to mitigate those aspects of a more traditional FPS and settled on this alternative approach.
Thanks for playing!