In this strategic game you've to prepare an army unit before launching an attack on the enemy castle. Command your army in the battlefield and try to reduce the enemy castle to a flaming pile of rubble.
Firstly, build a few units by Left Clicking on them in the Pre-Battle screen. When you think you're about ready, start the game! You'll be on the battlefield. Left Click on the names of the units in the deployment bar at the bottom of the screen to send out one of them to confront the enemy castle.
Plan your strategies carefully, and don't forget about the upgrades! Upgrading a building will improve the training of your units. Improve infantry in the Barracks, and archers in the Fletchery.