Enter the Gungeon

A top-down bullet hell roguelike where you play as one of several gungeoneers, delving into the six-chambered Gungeon to find the way to kill your past at the end. Fight your way down through multiple semi-random levels and shoot everything you come across with the incredible array of surprisingly gun-shaped weapons and artifacts, and get a bit farther every run.

You start each run with a unique character and starting loadout, and find new guns, accessories, and consumables as you progress through each level, which consists of enemy encounters, treasure, helpful or harmful NPCs, as well as money and shops to spend it in. You'll likely die many times before making it through all of the levels and endings, so unlock all the new gear that you an after every run, and maybe find some new friends in the gungeon as well.

Most guns and items have some synergies with each other, allowing you to alter their function for what usually becomes dramatically increased power. Nearly everything is some variant of gun or bullet, and the thematically similar ones tend to unlock new effects when you wield them both. Unlocking new gear, guns, and characters as you try to conquer the gungeon is what will eventually lead you to the treasure at its end.