What is this?
This is Wolfenstein 3-D: Alt-Right Edition.
Use the arrow keys to move, X to punch, space bar to open doors and start the elevator. This probably won't work on smartphones/tablets without a keyboard. This is the first shareware level, so it will only take you a few minutes to play through.
The source code to this is on GitHub, originally forked from id Software's generous source code release of a pure Javascript rewrite of the original game.
You can buy the real, full Wolfenstein 3D and its sequel, Spear of Destiny, from Steam or GoG.
You can play the actual, original 3 episodes of Wolfenstein 3D in a browser,
too! It's freely available at 3d.wolfenstein.com
You can follow @icculus on Twitter. If you want to explain to me why Hitler was a cool dude: don't.
(this is intended to use Wolf3D as a form of parody, please don't sue us, Zenimax.)