Theories by Murandliz.
The Player is Liz and Mur's Son Theory (debunked)
The Player is Liz and Mur's Son Theory
I believe that Mur ad Liz where married before Mur discovered the Submachine. They lived a happy marrige and once Mur found out about Submachine from his trip to Kent Falls. He wanted to try to explore it and Liz agreed, happy to help him along his way. They moved into the lighthouse after they were called 'freaks' by the community. Then they ran into Einstein, who was sent by Submachine to 'get the ball rolling' for the savior of Subnet(The player) and after stairing into the cats eyes, they felt a passion greater then anything else. The next morning, Liz woke up to find Mur talking about how he only wanted the power of submachine to 'take care' of his enemies. As she went to confront him, a portal opened up and they both fell into it.
After waking up in a strange room, their fighting began, but soon Submachine stopped it by sending them into different portals across the net. After Liz woke up in the Lighthouse she soon found out she was pregnant. Some months later she gave birth to a son, who played the 'test' game of Submachine(Sub1). But once he began older, he began to play around the beacon if the lighthouse(Sub2) causing him to get lost in subnet where he lost most of his memory by submachine so he wouldn't cause anymore fighting between his parents. So I beleive that the player is non other then Liz and Mur's own son, with the help of the submachine, trying to get back to his mohter Liz but being stopped and 'tested' by his father Mur. Mur only wanted his son because he could over come any puzzle Submachine could throw at him, while his mother wanted him to keep him safe from harm. Mur though, never actaully knew he had a son since he was born after they left each other. Liz wants to tell him, but doesn't becuase he's still crazy and attacking subnet. Once the player aloud Mur to go into the core(Sub 6), Mur told Submachine to 'erase' him. But the player was saved by his quick thinking and submachine who, after helping the player escape, contacted Liz since Liz and the Submachinet had teamed up to fight Mur. Liz then told him to go the Winter place(Sub 7). But soon Mur attacked, forcing Liz to esape and hopping her son did too.