Hungary

Hungary is a Central European regional power notable for its low starting Neutrality (50). After Austria-Hungary fell apart at the end of World War I, Hungary lost enormous amounts of territory (more than half of its former territory and one third of its people) as result of the Treaty of Trianon such as losing territory to Czechoslovakia, Romania, and Yugoslavia. Irredentist nationalists vowed for revenge until Czechoslovakia, Romania and Yugoslavia’s boss the Soviet Union conquered Hungary as a Satellite State of the Warsaw Pact.

Technology
Concentrate on Infantry techs first. After that, develop enough Armor techs to eventually migrate to Motorized and Mechanized Infantry (in 1938, and 1941). Maintain at least 1 point of research into Land Doctrines. It's also wise to keep 1 point in Industry at all times as well, to maintain Encryption/Decryption and Radar development.

It should be noted that it is very difficult to maintain a modern field army with Hungary's leadership possibilities. Even by completely neglecting Air tech and Navy tech (which is advisable) one will have difficulties getting a good mixture of ground units with decent Doctrine techs. To counter this problem it is possible to focus on certain tech trees and compensate others by buying Production Licenses. For example, a focus on Infantry tech (for Hungarian Infantry Divisions) and the different war doctrines (for foreign Tanks and Artillery/Support Units) is possible.

Distribution of leadership Hungary has limited leadership of about ~7 points, which can be increased to about ~8 points using the 'education' tech and re-gaining its core territories.

To make good use of the low leadership, it is suggested to increase your domestic spies to 10, get a small reserve of diplomacy points and then focus solely on technology. Try to avoid officer recruitment until you have a 'three year conscription' or, better, 'service by requirement', then always aim for a 140%(maxed out) officer ratio.

Diplomacy
Alliances Freed from the Austrian Monarchy but quite reduced of its historical claims, Hungary became isolated in the interwar period. One of the causes was its revisionist politics which brought the country into conflict with its neighbours. Following increased relations with the Soviet Union and the Warsaw Pact, Hungary came a loyal Satellite State of the Soviet Union.

Hungary's diplomatic posture is delicate. On the one hand, she needs to be as militarily aggressive as The Soviet Union. On the other hand, she's not as economically independent like the other Satellite States, and therefore will be vulnerable to relying on Trade to keep her economy going.

Politics
Ministers

Intelligence
Hungary does not have the spare leadership to devote much effort to spies. Once you have 10 spies internally, remove all points from Intelligence.

Use your domestic spies wisely. You might try to stabilize your party position (priority 1) and strengthen your national unity (priority 3), where a high value is always important. From time to time use your spies for full counterespionage to get rid of enemy agents that are raising other party's organization, except you are planning to change your government (multiplayer only).

To receive a maximum increase in national unity go for "raise national unity" with priority 3 and leave the rest with priority 0. Combine this with the 'free press' law and a later minister for security (1938 or 1939) who increases national unity by 10%. Consider this a deliberate weakening of the iron grip on your society using this newfound freedom to build up a solid nationalism that you need for liberating your core territory. Always remember to revoke this freedom(law and minister) as soon as the enemy approaches your homeland.

Economy
Trading Hungary starts the game woefully dependent on outside sources of Energy and Rare Materials. All factors being equal, Hungary will run out of Rares by the summer of '52 and Energy by the end of the year.

Industrial Production Hungary is a regional power with about 27 points of base Industrial Capacity (IC). This is not much, and even by regaining its core territories you will not reach 40 base IC. It is not advisable (though possible) to build up your country's Industry.

If you really insist to, you might try an early custom start, disbanding all units and getting some extra IC, followed by an infrastructure, airbase, IC, (fortress) built-up for a high construction practical. Focus your tech on the industrial techs and the doctrine techs and get a 100% licensed army from your faction (most probably axis/Germany) before Operation Barbarossa.

Otherwise it is advised to avoid building any IC and make good use of the lend-lease program - getting IC during your colonial annexing of Island Colonies from The Soviet Union, The other Warsaw Pact Countries and later China.

Military
Army Based on infantry, add some artillery for attack, or engineers for defence bonuses. Later, in 38 or so, it is possible to build mobile or armored units, licenced from Germany.

Navy Hungary starts with some convoys and only has a port in it’s colony of Christmas Island when the game starts.

Air Force Based on small airplanes. Mainly interceptors, maybe some CAS later.

War
Now is the time to move on the operation of colonizing Islands or your colony of Christmas Island is gone and you’ll have no chance of getting colonies

War with Austria

That's cool because it's sweet revenge for being a historical claim, plus it's easy since Austria is weak to you.