Similar to what was done with PSN titles including Supersonic Acrobatic Rocket-Powered Battle-Cars, a recent patent filing by Sony has been found for a new demo system that slowly degrades the game as it is played.
Essentially this means the more hours you put into a downloaded PSP or PS3 demo, the more the demo's gameplay diminishes.
For example, as you continue to play a video game demo, your weapons might decrease in value (size, quality, etc.). It's essentially a system that adds a time limit to a demo.
This new system is reportedly going to help people make the decision to buy the actual game instead of continuously playing the demo. Whether that will work or not is questionable.
To quote: "In one scenario your weapon is weakened or replaced with a less powerful one after so many hours playing the game. Think of it as a timed level down.
Another idea Sony has is to remove levels, race tracks in this example, after you reach a certain number of plays. When you finally buy the game (bottom right) you can use all of the tracks again."
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