The game is pretty cool once you get a hang of it. The graphics are really nice and I like the style and the music very much. My favourite strategy was to swap sides of goblins on the far back of opponent's forces, also tried to create a death squadron of sniper elves, but it didn't go as planned :D.
There were some bugs and exploits but it didn't hinder the experience too much.
Honestly I don't know if I can give a bigger praise to the game than saying that I spent way too much time on it... If a jam game takes 30+ minutes out of my day, somebody did a good job.
I would of course want to see more cards, more races/classes, maybe some elemental fields on the board etc. but as far as the jam version is concerned this is a solid entry for sure. Pretty light but clever use of the theme, and once again a great style.
When I first saw the WIP screenshots I wasn't really expecting what I got, but as a fan of card games I couldn't ask for more, and as a fan of puzzle games I basically created my own puzzles in the game and challenged myself to do something that well... I succeded: 
Once more, great job team :)