Unity is a cross-platform video game development engine that is most popular with independent and mobile game developers. Since Unity game developers tend to work on smaller projects, they're more likely to integrate blockchain into their games using off-the-shelf solutions, such as software development kits (SDKs).
In gaming, blockchains can be used to create and manage characters, in-game assets such as weapons, in-game currency transactions, and to run the in-game marketplace. Characters and assets can be minted as NFTs and traded inside the game or sold in external marketplaces.
Several crypto projects maintain Unity SDKs:
Decentraland (MANA) ($1.3 billion market cap) - Decentraland is a large metaverse and NFT gaming platform with digital real estate and collectibles. Decentraland offers several gaming SDKs for integrating into Decentraland.
Enjin Coin (ENJ) ($1.3 billion market cap) - Enjin is a blockchain platform and marketplace for NFTs focused on enterprise and gaming. Enjin offers SDKs for the entire in-game NFT character/asset lifecycle--from minting to the marketplace. Every token minted in a game using the Enjin platform is directly backed by ENJ, so items purchased in games running on Enjin are backed by real-world currency.
DareNFT (DNFT) - DareNFT is launching a solution for onboarding traditional games to the blockchain.