So there is Game Credits, Unikrn Gold, MObileGo etc, not sure how Enjin coin stands out? Gaming is big though....
Check the article by icotracker, they compared 10 gaming coins
https://blog.icotracker.org/top-10-gaming-cryptocurrencies-ico/
And this article on cointelegraph: https://cointelegraph.com/news/blockchain-best-thing-for-gaming-since-invention-of-internet
With Dmarket, a potential competitor in the future.