Since I hadn't heard of this piece before, it wasn't immediately apparent to me that it was released as an April Fool's joke. Although the Quake setting is portrayed in a tongue-in-cheek manner, the use of "special effects" in the opening sequence does a fairly good job of setting the right mood for anyone who remembers playing the original.
A little map-connection legerdemain ensures that any of the multiplicity of apparent options will quickly funnel you towards either a generic dead-end or to the main path of progress. You'll soon find yourself happily blasting away with a virtual shotgun, much as you would when playing the real game.
The randomized combat means there is a decent chance you will die before reaching the end, but it only took me twice to run the gauntlet and reach the ending sequence, where a mysterious figure lets you in on the joke and ends the game.
It's not much of a game, but I congratulate the author for the effort it took to put together the opening sequence, and the work as a whole is actually not too shabby for a first attempt. It's worth the time if you've ever played the first-person shooter it's based on, just for the novelty of having the experience translated to IF.