The Gilbert Campaign:
You need to have some knowledge to take down the diver and warship; especially when the air attack is around you. Store fire is the key point.
The Guadalcanal Campaign
One thing to note here in this level with lower ratings, players should allocate the weapons to take down the motocycle first when these two come up at the same time, and this will give chances for heros and soldiers to take down the invisible soldiers.
The battle I & II of Pearl Harbor are demo checkpoints, it is easy for players to get started, and to get familiar with the operation process.