Not sure if this counts but the Youtuber Drew Durmil a few years back ran Hearts of Iron IV's World War II with AI Only and no interference. Some of the differences were interesting.
Germany does divide the invasion of Poland with the Soviet Union and invades Poland on its own. No Non Aggression Pact.
Several smaller European Countries join the Axis(presumably so that they don't lose lives in the Nazi Invasions that were going to happen anyway).
Switzerland does not remain neutral and joins the Allies, unfortunately this is during the invasion of France and it is almost immediately taken over. So Switzerland loses the jokes about it being Neutral but is viewed as having joined the war and being easily defeated, probably being remembered as something close to how France is remembered for Surrendering OTL. Speaking of which...
France does not surrender and continues fighting. Unfortunately Fascist Spain wins the Spanish Civil War and joins the Axis. France is attacked from all sides from Spain, Germany and Italy and eventually are conquered, placing France in a position similar to OTL's Poland. Denmark also joins the allies but is quickly conquered by the Germans. Hitler does not attempt an invasion of the Scandinavian countries and neither the Axis or the Allies seem to touch them, though the Soviet Union(who does not join the Allies) does attempt a failed invasion.
Italy is much more competent, taking parts of France and being given land by Germany. They also conquer more of the north Africa.
Greece does a better job or fending off both the Italians and the Germans, this results in Britain sending more Troops to aid them, leading to Greece joining the Allies and also becoming a driving force in the war with the Greek Front being an important location.
Japan never joins the Axis but still invades China, however, the Soviet Union(due to no war with Germany at the time) sends aid to the People's Republic of China, and they take the country, pushing the Japanese out, except for a small portion which the Japanese are able to defend and keep.
The Soviet Union also begins invading countries, usually the Middle East to avoid conflict with Germany, however they then invade Romania and the Axis declare war on them as a result of Romania being an Axis ally.
Britain is able to turn the tide in Africa through their colonies and begin to push against Germany. America has remained Neutral even passed the original date of Pearl Harbor and them joining(This is due to Japan being too occupied battling China and Russia). However, their opinion of Hitler is very low(lower than OTL), and their view on Emperor Hirohito is actually much higher. FDR is still President when America finally does join the war, though its largely through sending Volunteers. They first take back North Africa and defeat Italy and then launch a D-Day in Spain. The Germans actually have success in pushing them back. This is where it ended but it seems an Allie victory would follow. It should also be mentioned that the Soviet Union and China were their own faction independent of the Allies and Axis.
Presumably Germany is defeated if a year or two after OTL. Interesting implications include Japan never being nuked and remaining Imperial. No Pacific Campaign and no Nukes(the Nazis were actually working on them but were still fairly far when they were defeated). So the Allies will likely pick up on the Nuke research and this time the Soviet Union is not a member of the Allies, so they'd be slower in recreating the Atom Bomb. Anime as we know it doesn't exist due to both the bomb being used not influencing Akira, Barefoot Gen and others while Manga doesn't exist the same way due to Osamu Tezuka not being inspired by American soliders leaving behind Disney comics in Japan during the war.
If there is a Cold War it would most likely involve the Soviet Union and China being fought by mainly the US and (most likely)Japan due to Japan still being powerful and being a longtime enemy to both nations.