I've always been familiar with Quake, but only as a multiplayer game. I've played a lot of arena shooters (I'm more of an Unreal Tournament fan), but for whatever reason I never got around to playing the real Quake. I didn't really expect much considering how badly DOOM has aged, especially in terms of level design and general game feel, but I was really impressed.
Quake holds up on all fronts. The gunplay feels good, the movement feels great, the enemy variety is pretty good, and the level design is a night and day difference from DOOM and DOOM 2. It's hard to imagine that they came out only two years apart.
Despite being copied a million times, I feel like Quake holds its own against modern shooters. I would recommend it to anyone who likes movement shooters, and I probably should've played this ages ago.
P.S: I HATE SHAMBLERS I HATE SHAMBLERS I HATE SHAMBLERS
I think the limitations of the Doom engine work both against and in favor of the game, the enforced limitations kind of "distills" the levels to it's bare minimum, pure creative level design, forcing the developers to work around those "barriers" as I've said, you can see this with older map packs like Alien Vendetta where the map makers were pushing the limits of what the engine could achieve. With the risk of sounding utterly pretentious, there's a sort of artistry to making good Doom levels and this is somewhat lost nowadays with limit breaking source ports like GZDoom.
I'm with you - a really beautiful vanilla map, that pushes the visplanes, is much more impressive than a limit removing equivalent. I'm not saying that the latter maps lack artistry, but vanilla requires that you look at your map from every angle in almost excruciating detail. The result -- to me -- just feels that much more intentional/authorial.
OK now I'm definitely sounding pretentious :p