Dirty Harry is based on the popular Clint Eastwood movie character of "Dirty" Harry Callahan (rather than the specific movie "Dirty Harry"), a cop famous for his use of a .44 magnum for doing away with evildoers, and for his catchphrase, "Go ahead, make my day." In fact, the game begins with a digitized sample of that quote. The game play consists primarily of side-scrolling action. Dirty Harry can punch and kick the copious thugs that assault him using their own fists, guns, baseball bats, nets, and dynamite. The hero can also pull is .44 and aim it in 5 directions in order to pick off enemies, but the ammo is limited. Further, Dirty Harry has a number of other tools at his disposal, provided he collects them. This is not a one-way side-scroller, however. There are some adventure elements as well, such as being able to walk through alleys to other streets and going through doors to enter building. Entering buildings provides even greater challenges, like snakes and laser flooring. Dirty Harry even takes the fight down to the sewer.