You start the game with 50 status points, which you can spend on the ten attributes of the girlfriend you are creating. These attributes range from the obvious (e.g. her physical attractiveness, the way she dresses, her mood, and friendliness) to the less obvious in terms of their effects in the game (e.g. how often she gets jealous, and how well she gets along with your friends). You can boost your favorite areas at the expense of others, and you are shown the computer's "overall rating" for your constructed girlfriend when you are done before the real game begins.
The game is played like a turn-based board game. Each turn, you have a choice of what to do or say to your girlfriend. If you want to take her out on a date, for example, you can choose form dozens of choices ranging from "come over" to more exotic locations. Once out on a date (if your girlfriend agrees to go out with you), you will be given a further detailed menu of multiple choices from which to choose your action - much like Romantic Encounters at the Dome. If you treat your girlfriend right and don't make a fool of yourself, you can increase your status points. But if you screw up, your status drops - and if it drops below her total points, she'll dump you. You can dump your current girlfriend anytime and construct a new one using your newly increased status points. Eventually, when your status reaches 100, you can construct The Perfect Woman to fulfill your ultimate goal in the game: get into the Big Party which only accepts "perfect" people.
Although billed as an adult game, GCS is much better than most other adult games you will find, since it does attempt to be much more than a juvenile "sex simulation." There are dozens of variables that influence how your relationship progresses, and the various attributes of your girlfriend do make a big impact in the game - create a "tough" woman who is not easy to please and whose mood is suicidal if you want a big challenge. Overall, I had fun with GCS, even though real-life relationships are far more interesting and multi-faceted than any computer program. Don't pin your hopes on this thing, but it should help elicit a chuckle or two :)
Note: Although released as shareware ($25 for registered version), this freely distributable version is identical to the registered version, so I have labelled it "freeware" to use the same method I used for all other shareware-identical-to-registered games on this site. The author created a multimedia Windows version of this game in 1999, but that version was sold as shareware and is no longer distributed.