i really love the game concept. i was lost initially but it was very fun once it all clicked.
honestly don't have many major stuff to add onto. it's pretty well polished, music and art is pretty chill, and there's quite a diverse number of synergies and depth to it. for my minor suggestions, it'd probably be helpful if the possible card choices was highlighted a bit as well as a speed setting for the enemy turn.
overall, very well done! i'm looking forward to the progress of this freecellatro.