From what I've seen of mobile games, in practice it means that it starts off fun and well balanced. Then after [x] minutes it starts to get a bit frustrating, and suddenly you're unable to make progress without sitting and waiting or banging your head against the wall. This presents a choice to the player. They can choose to put the game down until they unlock some power up that helps them pass the level. Or, they can pay money to receive the instant dopamine hit of getting back to the beginning of the "compulsion loop".

The real dystopia is that I'm 99% sure these games dynamically adjust durations, prices, and incentives based on the user's past behavior to extract as much money per hour of play as possible. Essentially a machine that identifies and preys on a person's weaknesses.