Because NFT games are not allowed on steam, developers of them are using bypass tricks to put them on here. Here are the basic methods:

#1. They put it on a page saying "COMING SOON" to advertise it. If you look at the linked video below, the person even find one that tells you to go their website to download the actual game. This way they have a place on steam to advertise the NFT game. These games may never be on steam and only use the store page as a way of advertising the game on their private websites.

#2. They release a watered down version of the game. Basically, the game is done, but they cut out many things of it. For example, pay to play to give advantage to people who buy the NFT characters. They do this by having the players go to the game's website to buy the NFT's to use them. Putting the link in the game to the official website is another bypass that developers use to bypass not having NFT games on steam.

#3. They have the game in early development, but will technically never come out fully, at least on steam. Again, it is a method of advertising the game on steam, technically even if they are not a actual NFT game. Again, they link to their game official website, so it is again technically not on steam. Many of the games off steam are full games you can play, but either on the epic game store or on their private websites.

Here, please look at this video. This person went into very good depth on some of the NFT bypass games on steam. They are really good at explaining them, much better than me.

https://www.youtube.com/watch?v=vMsCHgY7uxg

The video says there are 68 possible NFT games currently on steam, and i imagine that number will rise too.