Halo isn't necessarily down or out, but it's been a while since we've seen meaningful movement out of it. Halo Infinite was five years ago, and it recently ended its patch cycle for online play. We've gotten some novelizations since then, but not much in the way of major mainline releases.
On the horizonthis year is Halo: Campaign Evolved, which will add new content but won't be a completely new game. It's a remake, and folks are patiently waiting to see how it compares to the original, which helped redefine console shooters.
That said, there are still plenty of fans who love the first game, and consider it to be the crown jewel of the franchise. While you can technically play the Master Chief Collection and other ports on an Xbox ROG Ally, having it on more platforms would be ideal. Over on X, fans are loving Halo: Combat Evolved on Nintendo Switch.
As revealed by modder GeneralKidd, Halo: Combat Evolved (CE) is able to run on Switch, thanks to emulation. It runs in an ARM64 built off Xemu (an Xbox emulator), and it's the original version that's been ported over. Incredibly, GeneralKidd also has a video of the original...
