If you can get your hands on it for cheap, I'd suggest Out of This World (Another World in Europe). It practically defined "Nintendo Hard", but the atmosphere is top-notch. The unofficial SegaCD sequel, Heart of the Alien, sort of missed the mark in some places but had some absolutely beautiful scenes and music.
Also, Kairo is sort of weird and aggravating at times and doesn't exactly set benchmarks for graphics, but it can go from mysterious to oppressive to grand easily.
EDIT: Oh hey, Out of This World is on sale for $5 on Steam for the next two days.
Also, Kairo is sort of weird and aggravating at times and doesn't exactly set benchmarks for graphics, but it can go from mysterious to oppressive to grand easily.
EDIT: Oh hey, Out of This World is on sale for $5 on Steam for the next two days.