Ideas:

#1 Ninjas vs Pirates
Under the cover of night, several ninjas descend to the deck of a pirate galleon anchored in a cove. Silently they slip into the captains quarters at the back of the ship, and pick the lock of a treasure chest therin. As the lid to the treasure chest creaks open, a group of armed pirates rises up out of the shadows behind the ninjas.

#2 Mech Battle
An alarm begins to blare in the barracks of a base, soldiers clamor up ladders and along metal walkways, they jump into robotic walkers and make their way to the battlefiend outside their base. Laser cannons fire over their heads and missles are launched continuously until the invading army is demolished.

#3 Pen and the Sword
Two pirate ships meet in the ocean and one attempts to board the other. The two captains clash with steel on the deck of the defending ship. Each time one strikes, he throws an insult at the other captain, and to parry the strike the opposing captain must best his insult with another that rhymes.