Square Enix ported their mobile tactical RPG to the PC and made it available for free through Steam.
With over two million players on the mobile version, the PC version features cross-platform play with the mobile app. The game offers real-time multiplayer battles with players from across the globe as well as regular league battles and special arena tournaments for players to fight their way to the top of the PvP leaderboards rankings.

Features include:

Again, keep in mind that this is a port of a mobile game, so do approach with caution.