Stryder how do you know there are other "levels"?
Well if the aim of the game is to live, reproduce and attempt to succeed. It would suggest that one of the aims of the game is to make other levels to get to.
I theorised about it one day in regards to the old personification of Death. You know the suggestion that you can challenge Death to a game (a bit like Bill & Teds Bogus Journey). Obviously if the only way to continue your existence is to keep winning games (or in this case levels) then thats what you'd have to do.
Admittedly it goes a bit deep. I mean lets say we simulate the universe so that when we die we get put in the simulation. Obviously people aren't going to be necessarily happy with reliving the same life over and over again, this means that different universes would have to be formed where different outcomes occur. In fact it doesn't have to even be limited to the mundane existence we once knew, it could be a future or past life that we move on to in a simulated environment.
Obviously however when it becomes realised that we'd exist as proportion of our own future in such an environment, it's no longer viable just to "Exist" in these incarnations but to become Games "Avatars". It definitely throws a whole new twist on war and who's out to get you.
(Remember kids this is just a philosophical reasoning, I'm not suggesting you go out and shoot people... like I said there should be rules and Anti-PKing or TKing are obviously in there... along with the not quitting early commonly known as Suicide.)