In the near future we are going to see a huge rise in coins that are involved with video games. The video game industry is worth billions and currently we don't have any active gaming coins that I know of. Besides the one's in early stages of development.
Value of the global video games market from 2011 to 2020 (in billion U.S. dollars)
Number of video gamer players worldwide in 2016, by region (in millions)
Currency in games like runescape and world of warcraft have their own built in currency. And these video game currencies are actually bought and sold for real money. Currency in games have real demand with real markets. The problem with these game currencies is that they are controlled by the video game companies and can be manipulated and printed willy nilly. The game company can even simply take a players account and in game items from them despite the worth of the account being worth a great deal of money. A blockchain based game could possibly keep admins from doing that.
To see the potential for yourself look at the site playerauctions where gaming currency and items are sold. https://www.playerauctions.com/runescape-gold/
If a video game came out that ran on some sort of blockchain/ethereum token technology that particular gaming market would achieve massive demand because there would not be any centralized control of the in game currency or items. It seems like a coin similar to steem could work in a game. Completing quests could work like an upvote generating payouts from a reward pool.
Cards in card games like Magic the Gathering and Hearthstone have a huge demand but are in control by the companies that make them. These companies can create more cards when ever they want. And sometimes these card games simply don't allow players to buy and sell cards among each other for various reasons. This is why we need a card game that allows players to trade on a blockchain. If someone made a card game built with crypto coin tech that made it so cards cannot be created at the will of a developer but instead have to be mined in some way that would be perfect for a card game market.
Moving on from game currency and items the market for gambling is already huge for card games like poker. There has always been a want for competition gambling for video games but regulations always stopped them from happening. But now we have coins in development to solve this problem. Coins like 1st blood and peerplays are going to allow people to compete in video games for money. People have always wanted a place to play poker games where they don't have to worry about rigging. http://www.pokereum.io/ is a site that is making it possible.
I really think video game coins have the potential to leave bitcoin and ethereum in the dust, or bring bitcoin mainstream. If a game ever comes out that is as popular as WoW or Overwatch and uses some sort of crypto coin the amount of people using it would be massive. The people being introduced to crypto via games would also have a good understanding of how computers work and would likely easily understand what bitcoin is. The possibilities for crypto in the gaming world are endless.
A list of gaming coins:
1st Blood
PeerPlays
Nexium
Voxels
Skin coin ico