Based on a reviewer, here's the coverage.
Coverage:
Verbal Analogies
Reading Comprehension
Inductive Reasoning
Quantitative Ability
Perceptual Acuity
Biology
Physics
Chemistry
Social Science
You can also read the thread on filipino medical schools and they discussed specific topics where they are not confident. Some worry about the social sciences. Most would say the exam is easy. But this is relative as you are competing with your batch of examinees (curved test). If you want to get into competitive school like UST, you need to score well (in the 80's). Other schools usually accept between 55-65. Some don't look at your NMAT score and look at your grades.