The project is moderate difficulty. Not many business rules. It tests your abilty to design, code, interpret requirements, and your written communication. I think any degreed computer scientist should be able to complete it without much difficulty. However it is time consuming and the amount of time correlates with your java familiarity. Someone without a programming background either academic or professional would have difficulty and probably get discouraged and quit.
I would buy Habibi's book and if you understand the code samples and explanations, then you shoulsd be able to complete the exam, although the less experience you have, the more difficult and time consuming it will be.