I can understand now why ID titled this game "RAGE."
Spoiler:
You're gonna feel angry when you reach the end of it. If you thought you were gonna encounter the head of the Authority, some giant robot, or another giant Mutant like the one you met when you went into Dead City for the first time, you're not. Your "final boss" is apparentley nothing but a hand full of club wielding Mutants while you try to push some buttons. After that, a quick cutscene will come up and the game will end.