Redeemable against 1 of 3 copies in existence of Super Seducer 1 for Nintendo Switch. Super Seducer will never be officially released for Nintendo Switch but the owner of this will own a fully working ROM, playable on Switch.
The first ever full video game sold uniquely as an NFT. Not available in any other format. No physical or digital copies exist outside of the developers.
Possibly the rarest video game ever, limited to 3 official copies. Sold by the developer, Richard La Ruina.