The game launched with Generation 0 to initially bootstrap the game. Shortly after, Generation 1 was released which eventually minted out. Future Generations will be added when needed.
Gen 0 was minted with $AVAX at the static price of 2.7 $AVAX. This was a limited supply of 12k to bootstrap the game. Generation 0 have many existing and future benefits that no other Generation will have making them some of the most sought after characters in the game.
As the game grows there will come a time when Gen 2 is needed however there are no immediate plans for Gen 2 just yet.