Underrated is a perfect descriptor. As you said, it inspired a whole new genre that is flourishing on PC and other consoles, yet Metroid itself just doesn't get the recognition it deserves on Nintendo consoles because it's more adult and complex than typical Nintendo faire. Hell, Nintendo themselves don't even seem to understand what makes Metroid so good and influential, hence the craptacular spin-offs (Pinball and Federation Force) and poor creative choices (Other M).It's always been the most underrated franchise.It spawned a fucking genre.It has masterpiece after masterpiece in its library and it actually has a story.Don't get me wrong I love my Mario's and Zelda's but story in those games is the most basic shit for narative a game could have.Also the fucking music in Metroid is put of this world!