Urgent! Test for a job

[Morrino]

Hi, I just had an interview over Skype and they sent me a 3 page pdf file which shows the description of the currencies, the items and the buildings in a game.

Then they asked me to send him my opinion, and my proposal in a couple of hours. He want to know how I would get started if I were the designer of the game and had a crew of 5 people and a development time of 7 months or so (the crew and dev time was mentioned before the idea of the test).

So my question is, what should I write him? What is the idea of this?

Thanks in advance for the help