Well, not hidden so much as perhaps under-used... Anyway, some useful quiz features:
1) No going back: Sequential navigation
If you really don't want your students to go back to a previous question (bearing in mind they can actually do that in a paper exam) then set the navigation method to "Sequential" in the quiz settings layout. They will only be able to move forward!
2) No credit for lucky guesses: CBM
If you select CBM (Certainty based marking) Quiz settings>Question behaviour>How questions behave, you can reward students who took the trouble to learn the work and penalise students who try to cheat the system - while still being fair to those who are honest! Take a look at Using certainty-based marking in the docs.
3) Allow certain students extra time: User overrides
The User overrides feature is useful if you have, for example, dyslexic students who are normally allowed a specified extra time. It's available from Quiz administration>User overrides. Here, you can not only extend the timing of a quiz for individual students, but you can also add other concessions such as extended deadlines or an extra number of attempts.
Finally, here's a sample quiz with all the available standard quiz questions. It's on the School demo site, Mount Orange, and you just need to log in with the username parent and password moodle to try them out.