In Final Fantasy VII, Midgar is the futuristic ghetto in which the game's action starts. The city is the heart of the Shinra Electrical Power, Inc, a corporation who has built large reacters in the city that draw all of the life energy out of the planet. The first six hours of the game takes place in Midgar, where the corporation and its secret police are in a battle against the environmental terrorist group Avalanche, a battle that the majority of the cities downtrodden residents are caught in the crossfire of.
The city of Midgar should appear familiar to anyone who is a science fiction fan. The city's layout, of a literal upper class living on a plate that shadows a literal under class, apparently comes from the movie Metropolis, a movie that I have not seen but seem to have been absorbing subconsciously from every science fiction parable about utopia and dystopia since then.
Despite the fact that various parts of Midgar are infested with monsters for the game's need to have the ever present random combat, the actual plot presentation of the game shows the city as not being too incredibly bad of a place to live. Whereas the post-apocalyptic city depicted in the Gun Dream has a cruel upper class physically seperated from the masses, who live an existence that seems to be a never ending battle against monsters; the city of Midgar doesn't seem to be that different from many world cities, with a train system that even runs on time, and restaraunts, stores and theatre.
The fact that the game designers chose not to exagerate the brutality and oppression of Midgar make it even more telling symbol of the games themes of political apathy, corporate domination, environmental damage and the like.