What are some alternatives?
When comparing OpenArena and Doom, you can also consider the following products
Xonotic - Xonotic is a free (GPL), fast-paced first-person shooter that works on Windows, OS X and Linux.
Quake - Quake is a series of first-person shooter video games released by id Software.
Unreal Tournament - Unreal is a series of first-person shooter video games developed by Epic Games.
Call of Duty - Call of Duty is a first-person and third-person shooter series by Infinity Ward.
Counter-Strike - Counter-Strike is a PC-exclusive FPS video game developed by Valve Corporation.
Overwatch - Stylized team-based FPS