I've had the same thing. I think that is kind of implied by the name. 800Score, or Perfect Score. It's not 450Score.com. I expect the questions to be difficult. It is suppose to prepare you for the difficult questions the CAT gives you as you get many of the easier ones correct. If you aren't ready for the harder ones, you'll get them wrong and go back to the easy(ier) questions. Generally, the princicples tested are the same, but the hard questions put the same concepts in different forms making it harder to recognize that they want you to find the area of a triangle.
See this question for example that many people may not immediately realize is about a triangle.
Find the area of the enclosed region created by the following: x>=2, y>=3, y = -x+9.
Don't fret about it, but make sure you have the core concepts down cold.
GMAT_700
I just downloaded the Sample GMAT Math Section from 800score.com. I noticed that questions are much harder than GMATprep. So, I was wondering if any of you had the same experience?