Usually, the program is located within your hard drive icon. If your computer meets or exceeds the minimum system requirements, but firing the shotgun causes the game to freeze, you probably have another program with a conflicting extension. The video display is choppy or pauses often. Exit the game and turn off Virtual Memory, RAM Doubler, AppleTalk, and any other programs or extensions running in the background. Play an easier level so the computer has fewer monsters to keep track of.
Game play is slow or sounds disappear when action increases.
If after these steps you are still not satisfied with the performance of the game, check the number of fonts in your fonts folder. A Macintosh can have a maximum of about 136 fonts, but it will run optimally with a maximum of only 20 fonts in the folder. You may need to restart your computer. If after this, you still are not satisfied with the game play, your only other option will be to purchase more RAM, or upgrade your computer. Purchasing more memory is the single best way to increase the speed of the game.