Perhaps Sebastian was plugged into the computer when he banged his head in the accident. The computer had saved Sebastian’s memory in its own. It was possible that Sebastian’s memory had been stored on disks. While they were in the hospital, someone stole all those disks. They ended up at the Computer Fair. Michael and his dad bought those disks from there. By playing the weird versions of the games, Michael was retrieving that memory. In this way Sebastian entered the games.