I really like the card system of the game, it's a different style from what is usually thought in a fighting game, however it still contains the elements of a fighting game which is great!
Though some improvements could be added like, a higher quality model for the characters. A arrow to point at what card is being used in combat since it's confusing on what is doing what and when.
Some features that would be really cool to see is an energy cost. Since there's numbers at the top of the cards i assumed you had planned this but, using certain cards can then make it so other cards aren't useable, like using 2 kicks wouldn't allow you to use a block on the 3rd slot.
Of course deck building could also be pretty cool!