Haunted Halls: Green Hills Sanitarium is a hidden object game with some
elements borrowed from standard point-and-click adventure titles. The player
assumes the role of the female protagonist, a woman trying to find her
boyfriend after he disappeared while investigating an abandoned asylum. The
main objective is to collect a series of objects and use them to solve all the
puzzles found on locations related to the plot. The items are stored inside
inventory slots at the bottom, from where they have to be dragged and dropped
on interactive portions of the scenery to perform an action or complete a
task.

Some of the necessary tools are received after completing one of the hidden
object hunts, available on certain hotspots shimmering with red sparkles
appearing on several locations. They take place on separate screens, where all
the items from a list at the bottom have to be found amongst the assorted
paraphernalia cluttering the scene. The hint button is a jar with arcing
electric nodes at the bottom-right corner, showing the position of one of the
required objects when activated, but taking some time to recharge after use.

Places with green sparkles have one of the mini-games, taking place on
separate screens where mechanisms of some sort have to manipulated to solve
them. Several puzzle variations are featured, where the player has to rotate
circular sections of a picture to unscramble the image, rotate wires to
complete a circuit and finish other similar challenges. They can be optionally
skipped after a few minutes.

Haunted Halls: Green Hills Sanitarium