The prefect addition to an already perfect game.
What Brood Wars brings to the table is the continuing story of our heroes and their crippled factions, at the end of Star Craft there were no clear winners. The Zerg Broods were left without a leader and going rampant, the perfect setting for the expansion pack and its new units and campaigns. There is not much more to tell that hasn't already been told, this is truly an expansion pack since the gameplay hasn't change much, with brood wars there were minor improvements to the gameplay and AI. The difficulty level was hiked up a lot since Brood war is not an easy game, this game is for people who are experts or use cheat codes.
Graphically the game as not changed it's still pretty much the same, except that the game now assigns a variety of colors for your troops when in missions; you no longer use the perennial blue color when playing as the Terrans. The music is the same, not that there is anything bad with it, after 5 hours of gameplay it still is excellent.
There is only one flaw I can see in Brood War, and that is that it came after the original, Yes it sounds illogic. Hear me out, when Star Craft came out it made such an impact that I believe the expansion set just cant match, even though it is basically the same game but with improvements. Bottom line is if you haven't played Star Craft you have to get it and if you have it, then also get Brood War.