For a ridiculous example, imagine there was a clause buried in the fineprint that allowed the store owner to charge you $5000 to unlock the game whenever they chose to. Even if it were in the T&C, it would be ruled invalid because it was so unexpected.
Similarly, removing the right to play a game you have bought with money because you haven’t played it “enough” (according to the vendor) may also be considered unreasonavlble.