NFTs on Sui don't work exactly like those on EVM chains like Ethereum, but they can offer the same core features—ownership, transferability, metadata, and royalties—along with some unique benefits. On Sui, NFTs are treated as first-class objects, meaning they can store dynamic data and be updated over time. This gives you more flexibility, such as embedding logic or tracking in-game upgrades directly in the NFT itself. Unlike ERC-721 or ERC-1155 standards that are contract-based, Sui’s object-based model allows more scalability and customization with lower gas fees.

You can definitely build an NFT marketplace on Sui. In fact, several already exist—like BlueMove and Keepsake—where users can mint, buy, and sell NFTs just like on OpenSea or Magic Eden. Since Sui has fast finality and low fees, it's actually a solid choice for building marketplaces, especially for gaming or high-volume trading use cases.

To dive deeper and get started, visit the Sui Developer Docs: https://docs.sui.io/build/nfts

You can also explore the BlueMove Marketplace to see a real example live on Sui.