TheDreamingHawk wrote:
I don't even know what Gradius is

(it's a side-scrolling shooter by Konami. One of the earliest to feature a power-up system. Notorious for its cruel difficultly due to the power-up system that makes it very difficult to survive after dying on advanced levels.)
I suppose it could be a new game (like Gradius ReBirth).
But for retro games, there's Gradius for NES (as well as Gradius II, but that was Japanese-only), and on Game Boy there is Nemesis (strange, I think that is the only game in the series to use that name in North America) and Gradius: The Interstellar Assault, known as Nemesis II in Japan and Europe.