Once you eat a monster it's eyes are the only thing left until they return to the monster bull pin, and the monster regenerates back, comes out of the monster bull pin, and is on the move again though the maze. The monsters will only stay blue for a limited time, or until you eat them all. At this point you can eat the monsters for points effectively doubling the points from 200 to 1600 per monster you eat. Once you eat an energizer, all the monsters in the maze turn blue and run away from you. The first fruit, the cherry, gives a small bonus of 100 points, progressing to higher levels like the Key level you can receive as high as 5000 point per fruit eaten. You can gather a possible 14,600 points for each level, and if you gobble up a few fruits you add to the level.
Big points come when you eat 1 of the 4 Big flashing dots called Energizers worth 50 points located in each corner of the maze. Simply score as many points as you can eating the small dots all around the maze. Playing Pacman is easy to learn and hard to master (like all classic games).