That doesn't mean they aren't a contract. They're simply a contract where your only options as the buyer are to buy or not to buy.

That said, a unilateral contract like this can be treated somewhat differently by courts. See below.

> 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 unreasonable.

As I posted in response to someone else upthread, it would be an interesting case if someone actually did try to take a game store to court on these grounds. Contract law does include general rules about reasonableness, and courts are more likely to apply them for unilateral contracts like these where one party does not have the opportunity to bargain.