Definitely an intriguing start. The surreal art is a lot of fun.
After a few rounds, I started to recognize some of the cards and be able to pick the right stat to choose when they appeared. But whenever confronted with a new card, I always felt like I was just choosing a stat at random. I generally tried to pick a stat my card was high in but that didn't always work out well. The key strategy seems to be choosing a stat the enemy is weak in rather than choosing one you are strong in. This is especially true with the later cards that have a bigger gap between their strong and their weak stats, and where your own cards are often to weak to win in a 'strength vs strength' fight.
Could use some more presentation, sound and music obviously, but little things, like some kind of effect or animation on the cards to indicate who won a given round. Could be as simple as the loosing card drops off the screen.
minor bug report:
The numbers in the center that keep score are only visible in fullscreen mode. I actually played in the embedded window for a few rounds and was very confused and couldn't tell if I was winning or losing until I looked at the screen shots and realized something was missing.