4x for cinematics. System 7.6 or higher. 14.4 Kbps modem for Multiplayer option. Engaging storyline which actually figures into gameplay. Variety of unit types makes for flexible gameplay.
Different races require different tactics.
Free Internet competition play. Starcraft has the same general structure as Warcraft, in which the noble races of Human, Elf and Dwarf fought off an invasion of Orcs and their ilk. Sure, you could play both sides in that game, but everybody knew who held the moral high ground. To meet your scenario objectives you must mine ore and gas to assemble your buildings and manufacture your troops. Choose to build the wrong structure or the wrong soldiers and you could leave yourself vulnerable to attack at a critical moment.