MojoKid writes "When a game developer releases a demo, it's typically intended to entice players into first trying and then purchasing the full version. This is the stuff of Game Design 101 for most of us, but a crack team of cutting-edge gaming researchers at Sony have applied for a patent based on a novel concept: game demos that become progressively less fun the more you play. Sony refers to this as 'feature erosion.' The idea behind this dubious concept is that gamers will become hooked on a game while it's still in demo, then squawk unhappily as features and abilities they've unlocked begin to disappear. In order to prevent this, the player ponies up for the full version. A demo or program that provides limited functionality or play time is one thing; a game that's purposefully designed to take your progress away, in an admitted attempt to get you to buy once you've been hooked, is something altogether different."