Okie Dokie (1996)

Okie Dokie was the first original homebrew game written for the Atari 2600 by Bob Colbert. Okie Dokie is a fast moving puzzle game that challenges you with 30 preset puzzles and 435 random puzzles. It seems simple enough, turn off all of the squares. Well, there's a catch! Every time you select a square, it gets flipped -- if it was on it turns off and visa versa. To complicate things further, any square directly to the left, right, above, or below the square is also flipped.