You probably play a lot of shooting games where you have to save your ammo to shoot at the right time and to hit your target...
Auto-shooting games are very different because your character shoots his bullet without you ask him to. You'll never run out of ammo, but you can however be hit by enemies or their projectiles and lose some health or a life.
Your main task will be to lead and to guide your hero in order that his balls can reach targets. In Bug Rampage, for example, you have to kill many types of insects.