Oh hell, can it really be 20 years? Twenty years since Id Software effectively kickstarted the first-person shooter genre? Yes it can, because, to celebrate the 20th anniversary of Wolfenstein 3D, Bethesda has made it freely available as a browser game.
Of course, this slab of shooter history has been freely available in various forms over the years. However, this is a hassle-free chance to experience the early coding genius of John Carmac, who conjured a smooth 3D experience out of PCs when they were still running 25MHz Intel 286 processors. Bethesda has also recorded a podcast interview with Carmac, who went back and played the game for the first time in over a decade. Well worth a listen.
For now though, just click on the link to the browser game and show those mutant Nazis who's boss.