Japanese war tatics
One was the Japanese Kamikaze, or "Divine Wind."Japanese pilots would have an aircraft full of explosives . The pilots were usually young men who volunteered to carry out these attacks for their country, due to patriotic and religious doing for their country. They would fly their planes into targets such as warships and carriers in suicidal dive-bombing attacks.
German war tatics
The German Blitzkrieg, or "Lightning War" was also a major war tactic of WW2. This tactic was about speed and surprise. You would use heavy weapons such as planes and tanks. Germany would send heavy weapons in "lightning attacks" to an enemy's front line. These forces would penetrate defenses.
Guerrilla
Another tactic in WWII was Guerrilla. It is a small band of fighters who weaken their enemy with surprise raids and hit-and-run attacks. The Guerrillas would use small groups to quickly, but effectively attack enemy lines. It was kind of like how in the Civil War they would line up and fire, but this time it would just keep coming.
Bombing
All the countries used bombing. You did not have to fight and it was a quick and easy way with out loosing your own men.