I really liked it. Its a clever concept that all these people willingly put their survival in the hands of a computer, and that the computer was programmed to preserve the community above all else.
Its kind of like Asimovs 0th law of robotics. The computer was doing what it thought was the right thing, preserving the lives and hopes of its community without causeing any pain or distress. Its just that the terms of the program had unintended consequences for the people involved.
I just thought, originally the gate would have been inside the dome. The reason no one knew anything about it was that the computer erased it from their minds when it shrank the dome leaving the gate outside.
The computer must have started to realise that something was wrong when people were requesting information about the gate through the link when none of them should ever be thinking about it having no contact with the outside of the dome.
In some ways its the opposite of the Matrix. In the matrix people were living out real lives in a virtual world. In this the people effectively had virtualised lives in the real world.
I wonder if the computer was in charge of maintaing law and order as well. It anyone did anything wrong the computer would be able to make everyone, including the perpetrator, think that nothing had happened. This would lead everyone to believe that no one ever commited a crime, a utopian society, which would be easier to manage than having to have a justice and prison system.