Hopefully, it's possible to play "Connect5" at BK using the interface of Connect6. Of course, it is proper to do it in "Unrated game", "Not counted game" mode. If you want to test "Connect5" write to me or to Connect6 forum.
Illegal move (two pieces at the same line) means the immediate lose.
THE RULES OF CONNECT5
The rules are the same as in Connect6 with two differences: 1. It is necessary to place FIVE or more pieces in a solid row vertically, horizontally or diagonally. 2. It is prohibited for each players during the same move to put both pieces at the same line (vertical, horizontal or diagonal).
Motivation: The game is more close to Renju/Gomoku since it is necessary to place FIVE pieces in a row (not 6 as in Connect6). The three is not a threat to win in one move but it is necessary to close three from at least one side (if there is no own forced play). So, the game is similar to Gomoku/Renju, moreover, as rule, the playing is going at two flanks simultaneously. There exist wins by means of "fouls", for example, if to place by one move two fours such that the defending points are on the same line. In some sense, it is similar to fouls in Renju. It is very hard to win in early opening since to defend is more easy than to attack in the case of small number of pieces on the board. Therefore, the knowlenge of the opening theory has not significance. But in the case of big number of pieces on the board the possibilities for attacks are growing strongly because of "fouls" ideas.
The implementation of this game is very easy on the base of Connect6.