I think that all of it is very good. However, the 'Step back in time' is brilliant. It gives a clear visual image, which includes references to most aspects of the chosen topic. Searching for the clues is fun and when found the questions asked are clear and help to make connections easily. The possibilities in the classroom are enormous.
Tests take on a totally different meaning with 'Beat the clock'.
The questions are straightforward and require precise knowledge, not guess work. Because they're fun to do students will learn without noticing it. Students of all abilities should enjoy these. I would use them at the end of a section of work instead of a formal test or to replace a typical questions and answers session. I would also use the site instead of a textbook and allow students to gather information from it.