If the game prompts you to press Z and nothing happens, press Y instead. This is a German game, and the German keyboard layout swaps Z and Y (Z being a way more frequently used letter in German words).
Also known as Chain Reaction
Puzzle, 1995Shareware
Puzzle, 1992Shareware, Shareware
Puzzle, 1993Freeware
Puzzle, 1991Shareware
Puzzle, 1995Shareware (installed), Shareware
Puzzle, 1994Shareware (installed), Shareware
Puzzle, 1994Shareware
Puzzle, 1996Shareware (installed), Shareware
Also known as BOB
Puzzle, 1995Full version
Puzzle, 1993Shareware (installed), Shareware