The Wolf Age takes place 1000 years before the first two Myth games. The game will follow the life of Connacht the Wolf, a legendary hero in the Myth storyline. The Myth series uses a combined arms approach to its tactical combat, with a mix of ranged attacks and melee units. It's not a game where players harvest resources and build units.
Players start with an existing force and play through the scenario with it.
Myth III will be mission based, with 25 scripted missions planned. Multiplayer is supported and with the first two games proved to be quite popular. They claim that collectively, they've played tens of thousands of hours of Myth. That bodes well, and setting up Myth 3 as a prequel is an interesting idea. Go play Myth.