4 in a row (Drop Four)

Four in a row or Four in a line is a two-player connection game like Tic Tac Toe in which the players first choose a color and then take turns dropping one colored disc from the top into a seven-column, six-row vertically suspended grid. The pieces fall straight down, occupying the next available space within the column. The objective of the game is to be the first to form a horizontal, vertical, or diagonal line of four of one's own discs.

Recent changes:
Fix some bugs