Whoo hoo, this game is nothing but dot eating fun. You play the game one screen at a time, and each screen will be covered with dots, baddies, and will have a few logs thrown in to boot. What you are trying to do is either eat all the dots, or kill all the monsters. There are two basic kinds of enemies (plus a few more that will sometimes escort the bonus letters). The first kind is a sort of green clam, these are slow moving and pose little danger to Mr. Do. But the second kind is fairly dangerous, it is a purple cartoon snake, and it will make quick rolling attacks at Mr. Do!, you must dodge these, as your powerball is ineffective against a rolling snake. Both enemy types will sometimes transform into a purple sightless unicorn if they manage to remain alive long enough, shoot the unicorns as soon as they appear, because you cannot outrun them over long distances.

Mr. Do! has two things to defend himself with. The first is the superball, he starts out carry this, simply toss it at an enemy, and they will vanish (you can also bounce the superball off of walls for a higher score). Your superball regenerates as you eat dots and fruit, and it is often a good idea to use it as soon as it regenerates (to take out yet another baddie). Your other weapon is the logs that are scattered around the game board. Simply push them, and they will roll down the screen, taking out anything in their path (including Mr. Do! if you are dumb enough to get in their way).

You leave a line behind you as you walk, when you meet your own line (creating a box), any dots inside the box will be upgraded to cherries, while cherries upgrade to apples, which upgrade to lemons, which finally upgrade to pineapples. You don't have to do any of this fruit upgrade stuff at all, but is the best way to rack up a lot of points. You can collect letters to spell EXTRA to get a free man (just like all the other "Mr. Do!" games).