a game has life cycle, that means that the tokens can only last for a period of time, is that right?
SKARA is a free-to-play game such as League of Legends or World of Warcraft (around since 2004), so the plan is to keep updating it for unlimited time and also release new games in the SKARA Universe which will use the same currency, so it can last forever. What is called games as a service instead of a product.
There are a few examples that go even further. Ogame was released in 1999 and still keeps million of active players.