Pac-Man Plus

The programming is a lot like "Pac-Man" except that 
the maze is outlined in green instead of blue. The 
prizes that appear in the middle of the maze are cans
of Coke, cocktails, green beans, cakes, gift-wrapped
boxes, etc. 
Whenever Pac-Man eats an energizer, the ghosts not 
only turn blue but they also get apple stems on their 
heads. On later levels, sometimes only three of the 
ghosts turn blue.

The game plays exactly like the original except that 
there are various events (apparently selected at 
random) that may or may not occur after Pac-Man eats 
one of the four power pellets. These events include but
are not limited to: the maze's structure becoming 
temporarily invisible, the ghosts turning invisible 
while they are blue, or only three of the four ghosts 
turning blue. 

Developed by Namco/Midway