In spite of these and other limitations, the game was an extraordinary achievement, given that all program code and game data were on a 140KB floppy disk, and the game executed on an Apple II with as little as 48KB of RAM. In fact, Grigsby pushed the limits of the Apple II so far that there would not have been enough memory available without using SSI's proprietary RDOS instead of Apple's conventional operating system. The players faced a number of challenging decisions, but they had a variety of potent ships and aircraft at their disposal. Although the game relied on text for most of the interaction with the players, most players found high excitement levels during the combat phase. Program execution was surprisingly fast for a BASIC program on an 8-bit 1 MHz CPU, although later turns when most vessels and aircraft were deployed could take 4–6 hours to execute. Combat was intense, and losses on both sides were high.