Starcraft is a Real Time Strategy (RTS) game with 3 very different races but well balanced. The story is very good with a lot of cinematics, and the voice acting is amazing. Besides the campaign, you can also play custom maps which you can create with the editor you are provided with.
The difference in the 3 races lies in playing styles depending on the race you choose. You've got the Terrans who are a very mechanized version of humans, and who rely on mobility and fortified positions. They can build anywhere and their buildings lift off to find a better position or sometimes to flee the battle. The buildings can also be repaired by one or more of their main worker units (The SCV). The more SCVs repairing the building the faster it will be repaired. To sustain a bigger army you need to build Supply depots which are among the few Terran buildings that cannot lift off. Also if any Terran building catches fire, it has to be repaired, otherwise it will burn to the point where it will be destroyed.
The Zerg are an alien race who favor very high numbers to simply overwhelm its opponent. They can only build on sort of a living surface called "creep" that is produced by certain structures. The drone, which is the worker unit for the Zerg, transforms into the building when creating it. These buildings cannot move, and will slowly heal if damaged, because they cannot be repaired otherwise. For supply , the Zerg have the Overlords, which are flying creatures that can also detect invisible units. more