This code was largely written by Javidx9 / OneLoneCoder for Windows. As of this post I have ported it to Unix/repl.it and, as a bonus, added strafing. For high FPS run this in a small window, and for high resolution run this zoomed out.
I don't think this runs on repl.run and it doesn't work well on this post. Try opening it in the IDE.
I'm planning on adding colors, some more features, perhaps integrating it with my procedural generation system, or even making this the gameplay style of my Dungeon Crawler repl rather than top-down.
W,A,S,D - Movement
<,> - Look left and right
Shift - Move faster