Doha is definitely behind the memory losses. Maybe he started to gain consciousness after ...

Doha is definitely behind the memory losses. Maybe he started to gain consciousness after the others and due to some reason (jealousy is a simple explanation but it could be more sinister) he sabotaged them so they couldn’t win the game. Bada might be the “last one standing” because he managed to make Doha forget but it caused him to forget his other teammates (I think Doha was working on making him forget too hence the “memory issues” mentioned).

Makes me wonder what exactly is Doha’s save feature? The others seem to have tapes except Doha. Could it be that if he kills the killer he remembers? That’s the only thing I can think of.