Axie Infinity is probably the most popular NFT based online video game. It was developed by the Vietnamese studio Sky Mavis.
This game uses Ethereum based cryptocurrencies:
Axie Infinity allows new players to trade and battle the in-game creatures known as "axies" (digitized as NFTs). A new player has to purchase three axies. After purchasing these axies, each player evolves and breeds them. Upon winning fights, you can earn an AXS token that can be used to decide the game's future.
Since the launch of this game, the studio claims that an average player has spent over 400 USD on the game.
The major player base of this game is from Philipines.
Axie Infinity is available on all major platforms such as Andriod and iOS. The installation and setup process is a little long.