Rise of the Triad: Dark War
The option to disable the hud is built into ROTT. Just press the + key until it disappears. However, to get the game to run properly on modern computers I recommend you download GLROTT, a source port. It adds features like higher resolution textures, widescreen support, and mouse support with look up/down. The source port does NOT include the original game files. You'll need to purchase those from somewhere like GOG.