Really interesting twist on connect 3 games! I really love the depth behind the mechanic of being unable to place on the same column twice and it leads to some interesting strategy. Also just for fun I used the entire left half of the board to create a checkerboard pattern of squares and circles :p
It's just a shame that it doesn't account for 4 or 5-in-a-rows or horizontal + diagonals. With some animation and minor tweaks, it could have a lot of potential!!
Great game!