Medieval Conquest is a real-time strategy game where you are trying to rid a kingdom of hordes of monsters. To this end, you must construct buildings and hire heroes who will slay the beasts.
The heroes come in three types - fighters who specialize in melee combat, hunters who shoot from a distance, and mages who cast spells. Hiring each hero costs money, just as building new constructions; money, however, can be earned by killing monsters. The buildings include sanctuaries to heal the heroes, shops which provide them with better equipment, guard towers to shoot at beasts that wander too close to your base, and more. Note that you can upgrade buildings to increase their endurance, capacity or other things (e.g. the damage done by the shots of a guard tower.)
Your heroes are controllable like in most real-time strategies - you can select them and instruct them to move to a specific point. The heroes receive experience points and improve their combat skills as they fight enemies and train in the educational facilities you build for them. You can also buy them new weapons, armor, items and spells. You have to make sure your heroes are kept happy - if they have nothing to do, or feel they have inadequate equipment, they may get fed up and leave you.