Game Developer reports, according to several sources, Sony is requiring time-limited game trials from game developers if they want their videogames to be included in the PlayStation Plus Premium tier.
Apparently, this requirement will only apply to games that cost $34 / €33 / 4,000 yen or higher. These timed game trials must be, at least, two hours long.
The videogames under the prices listed above do not require such a trial. Similarly, VR games also do not have to meet this requirement.
Game developers will have a period of 3 months from the launch of the game to publish these trials, which must be available for at least 12 months.
Sony will also consider and evaluate whether, instead of these trials, a developer can release a custom demo for their games.