The sky's the limit in this Pet Dungeon... or it would be, if you were above ground. There is no room countdown timer; this time, you begin with all rooms and all Keeper spells available. Until you decide to let some Heroes in, the only risk to any of your creatures is a couple of Lightning Traps just outside the Hero-claimed area past the water to the northwest. Don't go there until you have some reasonably strong creatures ready to destroy the traps, and you'll be fine. Just build and build to your heart's content.
There is 1 Receive Imps magical item, so be prepared to find it and get 10 Imps free, so later you can avoid throwing away an X number of potentially experienced ones if you have a tried and tested worker amount.
Calling it "Masterpiece" is a little overboard considering the kinda tight space you need to operate in when it comes to building room. Especially when looking at the confined shapes of the island you are on.
References[]
↑Dungeon Keeper 2 : Prima's Official Strategy Guide.
p. 271.
Rocklin, CA:
Prima Games. (1999).
ISBN 978-0-7615-1805-1.