You will need to unlock everything that is contained in the 'customize army' menu. This includes all the upgrades for the Hero (including barrages) the various turrets, as well as the misc units.
With no unlocks this will run you about 15 000 tokens. Taking your hero to level 5 or so should unlock large percentage of the turret upgrades reducing the amount you will need to spend, although unlocks are random.
NOTE: Whilst not specified in the achievement description, this must be done with one of the core heroes (Kaiser Wilhelm, Phantom, Star Bright and Dark Lord). Unlocking all the toys for the DLC heroes contained in the Hall of Fame edition will not unlock this achievement.