Half-Life: Dreamcast is a PC port of the unreleased Sega Dreamcast console version of Half-Life.
The "Dreamcast" port of Half-Life featured a lot of stuff (textures, graphics, etc.) not found on the other ports. And it was almost lost in obscurity if not for this port.
Though it might not be perfect, a few flaws here and there; nothing a few patches cannot solve. :-)
Very much appreciate you working on this one and I hope you continue to improve on it.