Actually, there
is proof. Look closely at the letter: there's an attached file with a list of music for both Toonstruck
and Toonstruck 2:
http://tinyurl.com/252mv75
password: toonstruck
There's a full list of rooms that were to be in Toonstruck 2. Only the real Keith Arem could have access to this material.
And the whole thing about petition really makes sense: Toonstruck 1 was a commercial failure, so to make publishers interested in financing Toonstruck 2, Arem needs to prove that many people will buy it. He doesn't ask us for money, he asks us to confirm that we'll be interested in purchasing Toonstruck 2.