In each game you play, you have the option to add an additional 18 bullets to your arsenal, which equates to one extra magazine. If you possess one or more bullets in your inventory, they will automatically be used in your subsequent game.
The Quantum Matter Generator (QMG) creates items like bullets, more QMGs, continues, or a Quantum Matter Box (which generates random items when opened). Each map has three QMG spaces, and up to three QMGs can be used in a game. You can get a maximum of two ammo clips from the first two QMGs, with the third giving another item. If you collect a Quantum Matter Box, you need to return to the menu to open it, or it will disappear.
In the event of your character's demise, you will have the opportunity to replay the map rather than starting from the first one. It's worth noting that in the beta version of the game, you cannot die in the first map. This feature will be available in the full version of the game.