You can use these tools to make quizzes to test your friends' knowledge of what it means to be a European citizen:
https://www.goconqr.com/en-US/quizzes/10393236/edit
https://testmoz.com/
Word puzzle maker:
http://puzzlemaker.discoveryeducation.com/CrissCrossSetupForm.asp
Crossword making site:
http://puzzlemaker.discoveryeducation.com/CrissCrossSetupForm.asp
http://tools.atozteacherstuff.com/free-printable-crossword-puzzle-maker/