There are two different ways to look at the Entrance Exam demonstration.
There is a non-interactive version, which is a slideshow of the different pages of the test. This version will work on any computer.
There is also an interactive version, which is a fully functioning program which behaves in exactly the same way as the real exam in January, although there are fewer questions and they are different! This program may require that you download some additional software onto your computer.

Non-interactive version
Interactive version