Chain Reaction

There are many games named Chain Reaction, most are Atoms implementations, but at least three are Tetris clones of sorts (Columns or Puyo Puyo, where the name is quite appropriate).

Atoms

• Chain Reaction by A.R. Wright (1990) was probably the first Atoms implementation for PC (DOS).
• Chain Reaction by Stephen Taylor (1992) is for Atari ST.
• Chain Reaction by Jonas Olsson (1993) is probably the oldest Windows implementation.
• Chain Reaction by RDA (1996) is another Windows implementation.
• Chain Reaction by Frank Van Camp (1999) is for 32-bit Windows.
• Chain Reaction by Neil Fraser (2003) is one of the latest 16-bit Windows games I've ever encountered.
• Chain Reaction by Lee J Haywood has a long history. What you can download here is version 3.01 for 32-bit Windows (2006).

Columns

• Chain Reaction by Paul Margetson (1991) is a Columns clone for Atari ST.
• Chain Reaction by Thomas Pytel (1996) is a remake of Xixit with different graphics.
• A Chain Reaction (1998) is one of the few fairly authentic Puyo Puyo clones for PC.