The essence of the concept lies in the network's transactions of the corresponding cryptocurrency (we call it "gamescoin") which are confirmed by the software built into the gaming application.
The example for the demonstration and understanding of its work is simple. Try to imagine a video game (for example "OpenMarioCoiner"), where the reward is generated during the main game process and the application is engaged in confirming network's transactions. So, the only miner of such a cryptocurrency will be the participants receiving a reward for the corresponding gaming achievements itself.
By the way, there is an option to implement a learning game similar to
https://codecombat.com but only with the possibility of receiving the reward in cryptocurrency for the game's achievements. It is possible to implement chess game with cryptocurrency reward and achievements as an options.