Mystery of the Ancients: Curse of the Black Water [Collector's Edition]

An excellent experience all around. It's a classic supernatural horror story with superb graphics and animation, solid hidden-object scenes and excellent puzzles. There's nothing flashy or groundbreaking here, just a very good rendition of a beloved formula. Even the bonus adventure is good and adds a new twist on the style and gameplay.

Strongly recommended.

Note that this is Mystery of the Ancients #2. The first entry, Lockwood Manor, is not on Steam. It's also excellent. The stories are unrelated and you do not need to play them in order.