It is still doing a great job for a few frames, you could keep it more anchored to the state of the game if you prompt it. Much like you can prompt coding agents to keep a log of all decisions previously made. Permanenece is excellent, it slips often but it mostly because it is not grounded to specific game state by the prompt or by the decision log.
So, "it generates a game" somehow "it's incapable of maintaining basic persistence without continuous prompting per frame".
Also, prompting doesn't work as you imply it does.