Siliconera has uncovered a Sony patent filing that points to the development of game demos that degrade over time, giving players access to fewer and fewer features until they purchase the full game. The patent describes triggers embedded in game software that gradually disable game elements and features, with examples such as deleting or affecting the strength of weapons in an action game or removing tracks in a racing game. The patent also refers to subtler feature degradation, such as affecting a game’s audio or visual effects. While much of the patent language seems to refer to the design as encouraging purchase, there is also potential cost-saving element to it. Siliconera says the technology would also enable distributing demos on physical media that contain the full game but only allow access to specific features, with people then only having to purchase keys rather than buying another disc. Read more at Siliconera.