Even non-linear games like Grand Theft Auto, which boasts insane amounts of freedom that allows the player to do ANYTHING, or games like Fallout 3 which brag over 26 different endings, aren't really anything close to what they try or claim to be. At the end of the day, all those things players experience in GTA are the same things every player of GTA experiences, everyone will just experience them in different sequences, or in the case of branching they might have to play over again and team up with different characters. Less ambitious gamers will skip over things and miss out on parts. With Fallout 3's insane number of endings, there are really only a very small number of actual possible outcomes, it just takes your various interactions and involvements in several things that happen throughout the game, then strings them together into a closing epilogue explaining your impact on the world. This really isn't much more impressive than the fact that the digits 0-9 can be strung together in an infinite number of sequences representing the number 1 through as high as you can possibly imagine. There are thousands of potential variations for the closing epilogue for Fallout 3, but usually only two or three possible outcomes for each of the many scenarios that are being mixed and matched to makes those thousands of variations.

Even the most complex games are really pretty simplistic.