Visuals
1 ... graphics elements fits together maybe only do tiny color palette adjustment
2 ... maybe fit drawing cards at the center of the screen when drawing (easier to find)
3 ... very good distortion line shader
4 ... when start holding new card -> delay glow shader where this card can be placed or show no possible placement (reason: full automation of the game)
5 ... when mouse stop moving & card is hold still for x seconds -> start little card movement animation (so it wont feels so static)
6 ... option to see cards bellow pile on click (centralized with darken fade shader)
7 ... when gaining point to <mission completed> -> some text notification somewhere
Controls
1 ... card movement well tuned
Design
1 ... great idea nothing to add
2 ... remove option of discarding entire hand if you do not have to
Sound
1 ... fits the game, no feeling of repetition