There’s no point in using NFT for that.

What assets are games going to allow you to import? Just anything?

Or only from authorized issuers (like the original game dev and authorized artists)? If so then you have no real place for NFT, you already have Steam marketplace and equivalent where the game dev sets up or integrates with an online marketplace.

Want transparency in the marketplace? Use transparency logs, not blockchains.

If you’re allowing literally any NFT then this is no different from allowing people to import arbitrary assets, with the sole difference that some have a digital receipt attached.

Blockchains are really only useful for certain coordination problems among mutually untrusting parties who can’t find a common trusted 3rd party. For most game devs that trusted 3rd party is Steam marketplace. It’s really only if you want to share assets in both directions between specific games from specific other developers AND want to make them exclusive / player owned AND don’t trust marketplaces like Steam, that it MIGHT be relevant to investigate if a blockchain solution fits.