I know I'm not exactly neutral on this topic nor do I claim to be an expert, so don't take my word for it. That's why I would encourage @Empire Of Sight to get involved again in this discussion as he recently launched an NFT based game himself and could offer the "other" perspective. I did post a metaphor in another thread ages ago about the basics of what an NFT is, and here it is...
Check out the other responses in that thread as well as other did go into some more detail.
The longer version is, an NFT is a Non-Fungible Token. It's a kind of receipt for a digital asset, usually a piece of artwork, tied to a market revolving around a kind of cryptocurrency encoded into a blockchain. A blockchain is essentially a market management system that facilitates trading on this system. If you imagine cryptocurrency being to stocks what the stock market is to a blockchain, and that's the basic idea. Unlike the stock market though, profits can be made simply through interaction, like through a video game. The more people interface with it, the values of a blockchain and cryptocurrency increase as that value is determined by the size of the digital space that blockchain influences, and thus the assets held within it. Again, kind of like the stock market whare shares can go up of down based upon the economic conditions, the value of a blockchain and cryptocurrency can change based of the state of the digital landscape.
The short version is, it's an unstable investment at best and a scam at worst. It's people who run those blockchains and own the cryptocurrency who are the only ones likely to make any money because the have thier own digital assets grow the more people feed into thier blockchain, it's basically a pyramid scheme for the 21st century.