Sorry if I'm saying this, but is not very good to do the assessment without any preparation in regard !
There are 2 famous website where you can pratice a lot, personally I kept praticing every day for a month, before applying.
There some "games" exercise where they want to test your monitor / multitasking / reaction ability.
After there will be 30 random ATPL questions (no calculation, or maybe some very easy).
Then the Video interview (you'll have 3 questions and 1 minute each to answer).
I'm my opinion (that's my point of view), the "game" part of the assessment is only the 20% of importance.
Focus on the video interview, dress yourself well, be decisive when speaking.
And, I think, ATPL questions are also quite important, as they want to see if you are able to remember what you have studied previously.