I just launched an arcade section on one of my websites, and I've had great feedback from the members so far. However, there are only two games currently available, because we have a special high scores table that works with these two games. And, of course, more in the future, but that will take time. I fear that the members will be getting bored with these two games, and the arcade won't be as popular as it could be. Do we add new games without the high scores functionality, or do we just wait for more games with which the high scores functionality will work?
You should ask your websites visitors what they want. Personally, I would probably like more of a variety even without the high score feature.