Crimson Planet

An anonymous traveler of the cosmos finds himself at the foot of a mysterious tower whose doors are ominously marked with what appears to be a bloody handprint. The tower's few levels contain a handful of abstract puzzles, each requiring some species of pattern-recognition and -matching capability (occasionally guided with equally abstract hints), sorted out through use of the mouse. Finally, the tower reveals its true nature and delivers the traveler to the little red orb in the sky.