This puzzle RPG looks to be one of a kind! From the looks of the trailer, it looks like players need to align their monster cards with one another in order to flank enemies, and activate certain skills. It kind of reminds me of Tetris. The puzzle aspect revolves around coordinating your movement (since there is a timer) by moving your piece to the perfect position.
On a side note, I personally like how there is a download counter that displays what awaits players for every milestone reached. It sort of sets a goal and encourages people to try the game out. But to be fair, the trailer is from 2014, so it's safe to say that certain milestones have already been reached.