Unlike many of the mods we feature in the Spotlight, this one is fully vanilla-compatible and will even run under MS-DOS should you want it to - but it’s such a great example of what can be done in Doom even without all the fancy GZDoom extensions that I felt it needed special mention. After all, GZDoom is an engine that's meant to run vanilla Doom games as well!
Doom Zero was a nice surprise that came almost out of nowhere. Apart from a six-level demo that surfaced back in 2017, author DASI-I had quietly worked away on it for two years before suddenly announcing its release to coincide with the 25th anniversary of Doom II. His philosophy for its design was to find and use new and interesting mechanics within the vanilla engine while still respecting id Software’s base level design guidelines, producing a hybrid of modern and classic design.
As a result, Doom Zero is not a WAD that keeps your visplane count straining at 125 throughout or has a million fiddly little bits of sector architecture. In fact, the look of it is quite understated, usually sticking to relatively plain, simple rooms and corridors reminiscent of the first IWADs. You won’t ever find yourself in any giant arena fights with 666 monsters pouring out of hidden teleports - the maps stay small and manageable and they never outstay their welcome. Instead of impressing with scale, this WAD puts its ingenuity into smaller challenges and unexpected clever scenarios, using the elements provided by vanilla Doom and putting them together in new and creative ways to finds its own style despite the confines of the quarter-century-old engine.
As soon as the main menu melts away to reveal the first techbase map you’ll feel at home - little references to Doom’s shareware episode are scattered all over, with the WAD introducing its own ideas on top of the vanilla aesthetics gradually as the game progresses. Throughout the course of its 32 levels, the player is taken through techbases, marble castles, cities, terrestrial and hellish landscapes in original takes on familiar styles, and manages never to feel repetitive - a remarkable achievement considering only one level designer worked on this. I particularly liked one map called The Pits that’s fought between two high-rise buildings, giving a great sense of real-world location without having to over-detail. More unusually, the secret level “Meat” is an unsettling tribute to the history of id Software, and it’s followed by a second secret level that takes a page from the book of Episode 3’s secret level Warrens.
Several levels give you options in the form of what I came to call “choose your own adventure” sections, where you’ll be presented with three keys or switches, and approaching one will close off the others. The choice you make will determine the route that you take through the map - it’s such a simple idea, and easy to achieve using just the vanilla linedef actions, but it instantly gives the maps an interesting degree of exploration and replayability. And you’ll notice the previously meaningless gargoyle textures becoming much more useful here, being used to mark switches and pair them with the door they open - nicely solving one of the more frustrating elements of Doom 2 in a straightforward way.
Elsewhere, subtle tricks are used to great effect, giving illusions such as changing wall textures or a switch that has to be pressed twice with different keys for each stage. And yet these things never feel out of place, or like they’re drawing undue attention to themselves - they just make the player perform a slight double-take if they know the Doom engine, and make them wonder exactly how these things were put together.
Along those same lines, Doom Zero also has the cleverest secrets that I’ve ever seen in any WAD, rarely just asking the player to notice a slightly different texture in a dark corner or providing hidden doors that can be found by running along every wall belting the space bar. Instead, you’ll have to use your wits (along with platforms, teleports and hidden ledges) to access the strong powerups and additional supplies that are often placed tauntingly just out of reach, and it makes you feel like a genius when you finally work out how to defeat the machinations preventing you from reaching them.
Only a couple of things are truly new - an original Dehacked monster replaces the Wolfenstein officer, a floating skull reminiscent of the beta Lost Soul that blasts shotgun-sounding attacks at you through its mouth. It starts appearing towards the end of the game, and its mobility and hitscan ability makes it a dangerous enemy especially in packs - yet another thing that will force you to adjust your tactics. And the game concludes with a climactic fight that, in keeping with the standard throughout the WAD, takes the vanilla objects that make up the Icon of Sin and uses some creative trickery to repurpose them into something that we haven’t seen before. After that, an epilogue guides you to the end, revealing the true reason behind the WAD’s name and providing a very satisfactory storyline proposal that ties the strands of the Doom chronology together.
Doom Zero is a fantastic tribute to the original Doom and the design philosophies that make it such an enduring game - it respects the roots of Doom but complements the style perfectly with its own ideas. Despite being released so long after the glory days of vanilla TCs and megaWADs, it truly deserves to be counted as one of the classics.Doom Zero thread over on DoomWorld