The object of the game is similar to that of Pac-Man. However, as opposed to Pac-Man where the object of the game is to eat Pac-Dots, in Munch Man the object is to interconnect individual links to form a continuous chain. A level is completed when the entire playing-area chain is completed.
The player operates the Munch Man using either the keyboard or joystick. The object of the game is to completely fill each level's maze with interlocking chain links until the entire board is completely filled with one continuous chain. (In level 20, 40, and 60, the maze is invisible and there are no chains. Instead, Munch Man must eat all the TI logos in the invisible maze. This gives the odd effect of showcasing the maze at first, but slowly hiding the maze as the player removes the indications of the maze paths by eating the TI logos.) Four cunning Hoonos (the equivalent of Pac-Man ghosts) attempt to thwart Munch Man's efforts to complete his mission. However, Munch Man always has his "Energizer" (the equivalent of a Pac-Man Power Pellet) which gives Munch Man the ability to devour the Hoonos. The game ends when the player's lives are depleted.
Points are earned in the game in the following ways:
- 10 points are earned for every link of the chain made.
- 70 points are awarded for each of the four Texas shaped energizers eaten per level.
- 100 points are given for the first Hoono munched, 200 for the second, 400 for the third, and 800 for the fourth.
For each 10,000 points earned, an extra Munch Man is awarded. Although the play screen only shows up to four additional lives, the games remembers any additional earned and applies them to the total. Each level has a maximum score of 8,700 points.
Another unique feature that differentiates Munch Man from Pac-Man are the Hoonos (similar to the ghosts of Pac-Man) that Munch Man employs to prevent the player from reaching his/her goal. The Hoonos are different from level to level in both appearance and ability. For example, the Hoonos on the first level are not particularly cunning nor aggressive. With each higher level, the Hoonos not only look totally different, but they become much more aggressive. The Hoonos also become much faster with each level, eventually becoming faster than Munch Man. In addition, with each level, the Hoonos have a shorter vulnerable period (the time that Munch Man can eat them) making it more difficult for the player to complete the level and move on to the next.
Although the shape of the Hoonos changes with each level, the colors of them remain consistent. Each level has Hoonos colored red, yellow, blue, and purple. The red Hoono on each level is the most intelligent, therefore the most likely to eat the Munch Man. The yellow Hoono is the least intelligent of the bunch. However, to make up for its lack of intelligence, the yellow Hoono has the ability to disappear occasionally for shorts periods of time, making it possible for it to sneak up on the player when least expected. This only happens if all the Hoonos and Munch Man are on the same row, due to a four sprite per scanline hardware limitation in the TI-99/4A. Since the hardware limitation is per-scanline, not per-sprite, it is possible and often the case that the yellow Hoono is only partially invisible. It is rare that it remains invisible for long. There are 20 unique sets of Hoonos. Beginning with level 21, the Hoonos recycle shape.