Sega Dreamcast was a great era for Sega and the first console capable of running arcade games 1:1. It didn't have ports of arcade games, it had full on arcade games identical to the arcade like Crazy Taxi and many Capcom and SNK 2D fighters.
And yes, I've known about the Dreamcast/Xbox successor thing for years. Sega actually released quite a few games for the Xbox that are really good like Panzer Dragoon Orta, Crazy Taxi 3, and Shemmue 2.
I'm unsurprised someone did this. The Xbox came stock with 64MB RAM I believe, and if you're good enough at soldering you can remove the stock chip and replace it with a 128MB chip. People have been doing this already for years to allow soft modded Xboxes to play back 720p video streams in XBMC (Xbox media center- what turned into Kodi).
I have a soft modded Xbox myself and used to watch 480p anime on it, until I upgraded to a Raspberry Pi 3b with Kodi. The Xbox was filled with emulators and other "stuff" but unfortunately, it's clock capacitor is dead and that's basically CMOS for the thing, meaning if I turn the thing on I just get the dashboard instead of my modded XBMC interface. It also has a broken DVD drive that is stuck and won't open, preventing me from reinstalling the hack by loading a glitched savegame in Tom Clancy Splinter Cell. So I'd need to fix the DVD drive and clock capacitor before I could get it back to running the soft mod.
*Shrug* I have a retropie with emulators and it's way more portable, can run it at 1080p if I want, it is way smaller and lighter.
Still cool someone got a game running at 720p that isn't supposed to but this RAM mod people were doing in 2004.