Cryptogram (1982)

Author's blurb A Cryptogram...challenges your ability to decipher coded phrases or messages. Not wanting to generate an "unbreakable" code, we used a simple letter substitution. Each letter in the statement is replaced uniformly by some other alphabetic character...Spaces between words and punctuation remain intact. There are two skill levels in the game. User summary The relatively simple game Cryptogram was written by Ronald Marcuse and Lynn Marcuse. It was published as type-in source code for Atari 8-bit systems, in Compute!, Issue 20, January 1982.