Nice idea and there's potential, but it's pretty boring so far. Everything feels slow, there's no music to keep you entertained, every attack has the same sound and visual effect, character selection is tedious (dragging all the way from the bottom to the top...), and unit choice seems to have very limited impact, with only slight stats variations (why do grunts better than base purchased units?)
Your hand of cards may or may not be affected by what units you have. If it's the case, good, but since there's no indication of it anywhere, it's hard to know, or to make informed choices.
The mini-games were fun, though.