Such is the case with The Last Guy, which, in the lead-up to the game's release, featured the "developers" of the game, a threesome working in a low-tech development studio somewhere in the Himalayan Mountains that actually programmed the game. Well, them and their goat. It dovetails nicely into the game's "story" too, which speaks of a beam that transformed anyone it touches into a zombie -- all save for you, the Chosen One. The Last Guy in the world who can lead all those not transformed into a zombie to save zones that allow the survivors to be rescued.
And that's really all there is to the game. Donning a cape and moving with unnatural speed, you'll simply walk close to buildings and people will spill out. As you near them, you add them to a hundreds of feet-long train that follows your movements exactly. This of course presents some interesting issues when dealing with the increasingly intelligent zombies that roam all manner of locations in the US (delivered with actual top-down satellite images). Luckily, you have the ability to pull the entire crowd, snaking along the same path you traveled into a tightly-huddled mass to avoid enemy patrols. You can also sprint, but both actions require stamina, which refills slowly whenever you're not burning through it.
Adding a greater number of people to your train allows your stamina meter to grow too, so managing the line becomes an incredibly addictive little game of risk vs. reward. Can you scoot around that building to get into the alleyway to pick up more people before the patrolling zombie sees you and before he can get to your following train of people? Sure, you can pull the line in after you've made it to safety (if you're attacked by a zombie, it's game over, if the line is attacked, some will die and the rest will rush into nearby buildings to be picked up later), but the more people you carry with you, the longer it'll take to round everyone up.
Having a large train of people is important, though, because it allows you to pass through barriers that would normally block your path. They'll only break, though, if you have enough people in line, and as the levels grow the challenge becomes greater because there are more enemies around to gobble up parts of your line. To aid you, random power-ups scattered throughout the levels can make you invisible (though not your line of survivors), give you a stamina boost and so on.
And so you run around scooping up survivors, taking them to the escape zone... and that's it. Sometimes the simplest of ideas can be the most compelling, though, as The Last Guy so perfectly illustrates. The simplistic nature of the game is reflected in the visuals (you can hardly see your character, and the people you lead around and the zombies that hunt them are all carried out with minimal detail), and in the audio (a rockin' but minimal set of 8-bit style tunes loop throughout the background), but they work toward the game's charm rather than against it.
The Last Guy is a classic example of what Sony is doing to differentiate itself from other online services. Simple games contrast perfectly with the full game downloads on offer, and though The Last Guy is only $10, the lasting appeal of being able to collect VIP characters in the levels and rock online leaderboards gives it just enough weight to make it worth those ten bucks.