Surround (or Blockade) was a popular arcade game in the early days of video games. The format of the game is not complex in itself, but is still enjoyable and challenging. The object of the game is to build walls to trap the opposing player and force him to collide with: 1) his own walls, 2) the opposing player's walls, 3) the boundaries of the playfield. When this occurs, the player who did not crash receives a point. upon every collision, the walls of the play who crashed will blink. The screen is then cleared and the game continues.
Blockade for the Atari was written by Douglas Pinho and published as type-in source code in Compute! Issue 15, August 1981.