Complica (1991)

At first glance, this early Knizia title may seem like an easier version of Connect Four played on a 4x7 grid. However, in Complica, when a piece is placed, it does not remain there for the entire game. Another piece may be used to slide the entire column down. The winner is the first person to have 4 pieces in a line. The mechanic of the sliding rows means that each player can possibly have 4 in a row at the same time, causing the game to continue until this situation can be broken up.