Crypto-native business model
Traditional games typically make money by selling copies, offering subscription access, micro-transactions, or advertisements.
If you're building a crypto-native game (one where all data and game logic is on-chain and all code is open source), then most of these business models don't make sense. Micro-transactions are the only one that directly translates well. The others all assume some amount of centralization.
But this isn't the only way. If you don't want to charge money to play the game, you can still make a profit via royalties on in-game asset sales. With this model, players can earn cryptocurrency and/or NFTs while playing the game. Most of these tokens won't be worth much money, but the few particularly rare items will likely be sold on the open market.
This allows you to take a small percentage on item sales and earn enough money to support further game development. The economics of this will need to be balanced to your specific case though, because item utility, speculation, community growth, etc. can all have a large impact on how much you can make with this business model.
It probably makes sense to diversify your revenue from this one approach, but the concept of only making money when your players make money will appeal to your crypto-native players. You can't neglect the business model, but it should fit with the rest of your game. Just because you can make a lot of money from micro-transactions doesn't mean that players will want to support you in that way.
-Luke
P.S. Share the wealth. A truly decentralized business model will abstract your business away and pay anyone (including you) who fills the roles needed to keep the game running smoothly.