When Ellery is called to planet Gliese 677Cc by Minae Nomura, only to arrive at an abandoned base, she finds herself adrift in an ocean of secrets, with little more than a malfunctioning diving suit and a strange AI to guide her. You are this AI.
This is an incredibly atmospheric game, despite the minimalistic approach. This is accomplished by having great writing describing each "spot" in the map, great music/sound effects that convey the mood superbly (helped by subtle palette changes). Take your time and do the graphics in your head, this is an amazing place to visit.