Too Long; Didn't Read
A few days ago, I discovered an online trading card game called Gods Unchained, which is backed by <a href="https://hackernoon.com/tagged/coinbase" target="_blank">Coinbase</a>. You can <a href="https://godsunchained.com/?refcode=0x070F37D2f866311f7b96b6C9e8B2755498c1eB45" target="_blank">buy cards on their website</a> and battle against other players using your cards. Cards are implemented as non-fungible tokens (ERC-721) so you can buy, sell and trade in a marketplace like Rare Bits. I dreamed about online trading card games like this when I was a kid, where it has properties of physical cards such as being able to buy, sell and trade your cards without the card issuer supporting such features and other businesses being able to freely build something on top of the card game e.g. hosting a tournament.