Goal: Conquer a map by destroying the enemy's base, or destroy other specific objectives to win.
Means: Direct control of a single Demigod. Each earns experience for killing enemies, which they can spend on acquiring new or improved abilities. Gold is earned for killing enemy, Demigods. This can be spent on buying armour or items to give a tactical advantage. Many combinations of items are possible. Four of the Demigods are able to purchase and summon controllable monsters that can heal, attack, or provide defensive bonuses. Assisting every Demigod is non-controllable groups of monsters that spawn at specific intervals from capturable portals. These mobs can be improved or upgraded by spending Gold at your base (do you spend gold selfishly on yourself, or help the team?).
It sounds simple, but there's a huge amount of depth, and maps play differently from one another. There will be a demo in the future, so just wait for that if you're still on the fence.