Nice idea. I think you should more explicitly say what counts as an alternate name. Some would include countries with ___ and ___ (Antigua & Barbuda, Bosnia & Herzegovina, etc) or countries that only require a keyword to be in the answer (North Macedonia, both Congos, F. S. Micronesia, though 3/4 of which also have acronyms).
The caveats say that countries that commonly go by a short name are omitted, like "Congo" or "Bosnia". This quiz is more about abbreviations. Otherwise, I'd have to include Antigua, Sao Tome, etc., etc., etc.