I really like the GUI , is it just Morphic ?�
Your impossible mode is quite easy to win.
One thing I would change is when I use the ToggleMode to toggle to Player vs CPU I would like it to stick even after I finish the match. Because as it is now If I click New Game it reverts back to Player vs Player mode.
Also I would like if you expand your window to add the bottom text because as it is if it mixes with other windows its hard to read being outside its window. �