What are some alternatives?
When comparing Team Fortress 2 and Overwatch, you can also consider the following products
Warframe - Ninjas Play Free.
Xonotic - Xonotic is a free (GPL), fast-paced first-person shooter that works on Windows, OS X and Linux.
Doom - Doom is a science fiction horror-themed first-person shooter video game in which players assume the...
Quake - Quake is a series of first-person shooter video games released by id Software.
Arma - Experience true combat gameplay in a massive military sandbox.
Unreal Tournament - Unreal is a series of first-person shooter video games developed by Epic Games.