Good quiz, but try to be consistent with singular/plural for items and their respective answers. As what what mentioned previously, there are a couple that could be multiple answers like Europe for continent, as well as B-52s for Letter + Number
Please change the coloring of this nice quiz - I find the combination of purple font on blue background visually quite challenging and disagreeable. White font would make a difference or a brighter background.
A few ideas, "enlightment" should be "enlightenment". It would also be nice if the hints were plurals when the answers are