I'm quite astonished that they have managed to make it past three gyms already. I suspect that the game will eventually be beaten, but only after a while and after going through several ' cycles', so to speak.

I imagine that each cycle will consist of a mass of people becoming bored with the lack of progress and leave. As more people leave, it becomes easier to control the character, leading to progress being made. Howevere, once progress is made and certain milestones are reached, the interest will again grow and the players will increase again. Eventually, it will become too dfficult to play and interest will wane again; allowing the cycle to repeat.

Thus, I think it will eventually be completed, but not for a while. I'll be following it with interest however!