You are to create a mock-up of an oblique game. Make sure that all your angled lines fit the perspective (45 degrees, as per the examples shown below).
An example of an oblique cube:
Some screenshots from real games that use an oblique perspective:
Also, have a look at these oblique mock-ups by PixelJoint members:
Canvas Size - Unrestricted.
Colours - Max 32.
Transparency - Optional.
Animation - No.
The challenge thread will have all the challenge updates. The thread is also a great place to post your WIPs.