Back to Warcraft: Orcs and Humans
This is a non-base building mission. You must take your army of 5 Knights, 5 Footmen, 5 Archers and 2 Clerics into the tower to kill the evil warlock.
There is nothing difficult about this mission if you keep your army close together. Draw out the Fire Elementals with a Footman and let the Archers deal most of the damage. Repeat for all the enemies on the map. Once you get close to the Warlock rush him with all of your remaining army.