Back in 2001, Sega published the Smilebit-developed real-time strategy title Hundred Swords, a Dreamcast title which would sadly remain exclusive to Japan.
Like many Dreamcast games, it featured online play – a feature that was lost when Sega shut down its servers decades ago.
Now, thanks to the efforts of Shuouma, an individual who has done much to revive Dreamcast games from their offline fate, Hundred Swords is finally playable online again – provided you have the setup to do so.
The catch here is that the game is entirely in Japanese, but the gameplay is simple enough that you can figure out what you're doing even if you can't understand the language.
There's hope for a Western translation, however, as the game was also released in Europe and North America on PC.