It is difficult to overstate how much AAA games have become linear, scripted experiences. Games need to have scripting, and heavily scripted ones are nothing new, but some of the latest (especially first-person shooters) seem to be designed for the lowest common denominator of gamers. Allies are designated with a perpetual "Follow" icon, doors frequently have to be opened by NPCs and not the players, and it is often headache-inducing to deduce what specific series of steps we need to take to trigger the plot. The list of 'sins' can go on and on - monster closets, anyone? I had some rather pointed remarks elsewhere about the level of scripting in Call of Duty: Black Ops and the game's relatively high review scores seemed to hinge on the fact that its scripting was less transparent than the glitch-prone scripting of, say, Medal of Honor or Homefront.
To a certain extent, this is an unavoidable problem. Even 'sandbox' shooters like the Halo franchise unfold in a basically linear fashion; simply criticizing a game for being 'linear' says little about the experience. When there is one - and only one- solution to every level, however, things get stale rather fast. Instead of interacting with a game world, we solve a puzzle created by the game's designers. The minute we realize progress depends on a very specific trigger immersion is broken.
The classic PC game Deus Ex has long been held up as a game which offered the players a multitude of solutions. Alongside games like Thief: the Dark Project and the System Shock series, these were "immersive sims": game worlds inhabited by the players, with a very real sense of cause-effect, and the freedom to explore that relationship. It remains to be seen if the upcoming Deus Ex: Human Revolution can be called an immersive simulation, but it certainly goes a long way towards offering an antidote for the hyper-linear game experience.
Shooters, whether first or third-person, frequently include 'stealth' levels, but in Human Revolution nearly every level is a stealth level if you are willing to explore. It might not be possible to make it through the game without killing a single person, but those seeking a non-violent path will have much greater freedom than nearly any game on the market today. At the same time, while the game can be considered to have role-playing elements, it is not a typical RPG either. Being a sci-fi, gun-focused action-RPG would make the game superficially resemble Mass Effect 2, but that game's combat played out nearly the same way every time. The story was excellent, but choice was not offered in combat. Deus Ex offers choice in combat, a design element that should not be as refreshing as it is.
To get a sense of exactly how choice in relating to combat is offered for Deus Ex: Human Revolution, the game's designers provided a narrated walkthrough/trailer of one level taken in three different approaches. Interestingly enough, despite the franchise's PC heritage, the trailer was filmed using the PS3 version of the game.
Check it out (violence ahead, so be warned):