Looks like there's a new threat rising in the land of Arcadia: Minibosses! Boss Monster: Rise of the Minibosses is an all new standalone set that can integrate with the previous two Boss Monster Base sets and all previous expansions.
As before, players will build up their dungeon (with graphics inspired by classic videogames) in order to lure in heroes and defeat them before they reach your boss. New mechanisms such as the all new miniboss room cards will power up your dungeon in insidious new ways, and wreak havoc on your opponents' dungeons.
—description from the publisher