We got Grand Theft Auto: Vice City on the Dreamcast before we got GTA 6.
The development team that ported Grand Theft Auto III (GTA 3) to the Sega Dreamcast late last year released a beta version of a Dreamcast port for Grand Theft Auto: Vice City (GTA: VC). The port, which was released on GitHub on April 1, runs on actual hardware.
As its GitHub page explains, the port requires a retail version of GTA 3 or GTA: VC to create the Dreamcast image file. The GitHub page specifically mentions the PC version of Grand Theft Auto: The Trilogy as a viable basis for building the file. There are two other tools needed to create the image, and links to these are available on the GitHub page.
Falco Girgis, one of the developers behind the project, posted a short gameplay video on X. The game is playable, although there are strange graphical glitches and the framerate is inconsistent. However, issues like these are to be expected since this is a beta release. Work is ongoing to iron out these issues and add features.
Key features in the beta include an option for 2x FSAA to smooth out edges and rendering with a 24-bits-per-pixel (bpp) frame buffer for "extra depth and vividness to the colors," according to Girgis.
You can check out the beta version of the Dreamcast port of Grand Theft Auto: Vice City at the project's GitHub page, linked in the Sources section below.