Video games, tv, and movies tend to focus on Nazis as the lead villains, but seldom address other Axis Powers. Why is that?
To answer this is not as straightforward as I would like, and I would like for someone to give a more comprehensive answer to this question. Pop culture tends to focus on the Germans as the main villains much more often because it was Nazi Germany that had committed the most crimes against humanity, fought the war on the most fronts, and most importantly, conquered huge swathes of territory from multiple countries like Poland, Norway, Denmark, The Netherlands, Belgium, France, Yugoslavia, Greece and finally large swathes of the Soviet Union. We have many more accounts of the occupation, especially from the eyes of Western Europeans living under Nazi Germany. In contrast, for example, we dont have many accounts of Chinese, Koreans or Filipinos living under Japanese colonial rule, so we dont have enough narratives that shape their experiences during WW2. We dont have enough accounts of the KMT or the Malaysian guerilla resistance fighters either, since European-dominated narratives populate much of our cultural consciousness.
It was also Nazi Germany's occupation policies that left the deepest impact upon the population of these many areas. Whilst Fascist Italy led its own conquests of expansion it was nowhere as successful as Nazi Germany's (only affecting areas like Albania, Greece, and in Africa, Ethiopia and Abyssinia).
In October 1943, Italy switched sides when it was clear the tide was turning in the Allies favour. This meant Italy was definitely on the side of the Allies for the significant part of the remainder of WW2. This was actually a very messy affair, with elements of the army still on the side of the Axis . In a way it was more like a civil war occurring while the Germans and Western Allies fought each other on Italian soil.
Occupation policy: Although it was harsh and brutal, it did not reach the genocidal levels of the Third Reich. In many cases fascist Italy even refused to hand over Jewish peoples to Nazi Germany.
Sphere of influence: as I have mentioned earlier, Italy's successes were fairly limited throughout the course of the war. They had managed to occupy parts of Ethiopia and Libya, and Albania and parts of Yugoslavia and Greece. This is in stark contrast to the much more successful Nazi Germany.
Failure in war: Italy had never attained the level of industrialisation and mobilisation many of the other European countries had. Its armies had been insufficiently mobilised and the Italian army lacked a strong officer corps that so distinguished the Wehrmacht and its capacity for warfare. As a result, the Western Allies won multiple battles against Italy, from North Africa, to East Africa and Greece (to even their failed invasion for France despite Nazi Germany's already successful invasion). The British even carried out the Taranto Raid on Italian soil in 1940, damaging a significant number of Italian cruisers.
Polarisation: Italy was surprisingly divided during the course of WW2. Anti-fascist sentiment was increasingly growing in Italy, with failure after failure demonstrating the futility of conquest and the growth of Mussolini's empire. Partisan movements beginning to turn on the regime. It was so much so Mussolini was deposed by his own government. This gives the impression that Italy as a whole was ambivalent to warmaking and had a significant populace that desired peace.
(Edit: a few more points)
Fascism vs National Socialism: Italian fascism contrasts itself to Nazism. Wherelse Italian fascism stresses the unity of the nation and its people, National Socialism stresses the unity of the German race. There is a very distinct racial nature in Nazism that Italian fascism lacks. Although militaristic and jingoistic, Italian fascism does not denigrate entire ethnicities as subhuman or as "life unworthy of life". This adds an additional reprehensible layer to Nazism.
Warmaking experience: as said, we have far more accounts of engagements with Germans than Italians, due to the abovementioned factors. Nazi Germany fought on the most fronts, against the largest number of Allies over the longest period of time. and shaped the views of the most combatants throughout WW2.
Popular consciousness: the Holocaust and its industrialised mass killing adds an eerie layer to the Nazi regime. The Italians did not systematically exterminate entire groups of people on the basis of their existence.
Ethnocentricity: We salways get the side of the Western Allies, and to a lesser extent the Soviet Union. Seldom do we get the accounts of Chinese fighting the Japanese occupation. I believe that it is due to our biases and the biases of the media as a whole to favour a Eurocentric viewpoint.
Under Nazi Hawk, the small "hubbub" groups in the Axis are trapped in troubled territory, minorities and deep hatred. In this era, there must be a story in this area. But OP's problem in this area is very simple, why there is no such thing as "video games, television, and movies," because the average Western audience and mainstream entertainment producers know little about the region and its population. The events that took place during the war have fueled the fire and are considered to be a very important part of the history of the country concerned.