What island is the Haunted House on in Poptropica?

No. "Haunted House" is a maxi-game that was released in October, 2009. It is still available free in the Poptropica stoe, along with a short free game for "Earth Day" (April, 2010).

The completion of the game awards 50 credits. The only other value is the collection of Halloween costumes available to be freely copied : witch, purple witch, vampire, scarecrow, reaper, mummy, ghoul, and skeleton.