I have posted before on new mechanic suggestions that deal with the puzzle quest aspect of the game, but realize that minimal adjustments on this would be good. I would really like to see cards that generate activate gems that make the activated gem be able to flip diagonally for matches. 
I would like to see diagonal animated rings around the activated gem.
Same idea with any color gems. They could be generated from colorless supports based off of land cards.
and speaking of animations, it would be great to have foil versions of cards with sparkling animations.