Okay, I'm screwed on this one. I know Europe. I am pretty familiar with the North American Continent.
Asia, though....that's an awfully big place and I haven't visited most of it. Only place I'm less familiar with would probably be Oceania.
Well, I'll give it a shot...no guarantees of success or anywhere near it though. As usual...please excuse my spelling.
Russia
Turkmenistan
Kazhakstan
Georgia
Turkey
Kuwait
Lebanon
Jordan
Syria
Iraq
Iran
Israel
Palestine (technically part of Israel)
Yemen
Saudi Arabia
Qatar
Bahrain
UAE
Oman
Cyprus
Pakistan
Afghanistan
Nepal
India
China
Mongolia (though this may count as part of China)
Japan
North Korea
South Korea
Taiwan (also a different China)
Vietnam
Cambodia
Thailand
Laos
Myanmar (or Burma)
Helpful hints if you try to name them from memory.
1) There are 7 -stans; 2 of them start with T and 2 start with K.
2) There are 8 small countries easy to overlook (at least for me); 3 of them start with B.
Bahrain, Bhutan, Brunei. Also Qatar, Kuwait, Singapore, Timor-Leste, and the Maldives.
Okay, here we go! I'm sure I am missing some, and there might be a couple that I am placing in Asia that should be more properly elsewhere, but....
Russia
Turkiye
Uzbekistan
Kazakhstan
Kyrgyzstan
China
Mongolia
Afghanistan
Pakistan
India
Sri Lanka
Bhutan
Nepal
China
Bangladesh
Thailand
Laos
Myanmar
Georgia
Iran
Iraq
Oman
Qatar
Saudi Arabia
UAE
Yemen
Israel
Jordan
Lebanon
Syria
Bahrain
Malaysia
Indonesia
Philippines
Japan
Vietnam
North Korea
South Korea
Singapore
Taiwan (if we're counting it)