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.

Good effort! It kept me engaged for a fair few rounds but it did feel a little easy. I hope you keep developing this.