There was this story I read ages ago when I was young, and I cant remember the title. It's probably based more for kids than adults, but it popped into my head and I want to remember it.
The story is about two boys who are inside a video game, where they have to shoot the enemies attacking them like an arcade shooter. They hide inside a cave on a cliff face, and the enemies lean over the top of the cliff to shoot at them, while the players peek out from the cave to shoot up. As they play, the two players hate each other more and more until the main character guy lets the other one get killed. The one that died returns as a powerful enemy with the ability to climb down the cliff face to enter the cave.
That's about all I can remember, but if anyone has an inkling as to what story I'm referring to, that would be lovely.