“Give us more guns!” is a common battle-cry among players of first-person shooters, the videogame industry’s bloodiest genre. Doom co-creator John Romero has a rather different opinion.

“I would rather have fewer things with more meaning, than a million things you don’t identify with,” he says, sitting in a Berlin bar mocked up to resemble a 1920s Chicago speakeasy. “I would rather spend more time with a gun and make sure the gun’s design is really deep – that there’s a lot of cool stuff you learn about it.”

Over two decades since Romero, John Carmack and the other founders of id Software inaugurated the first-person shooter with Wolfenstein 3D, the genre has changed beyond recognition. Doom’s grungy hellscapes have given way to the authentic militarised killing of Call of Duty and the Pixar stylings of Overwatch. Romero himself has been somewhat estranged from shooters since releasing the widely panned Daikatana in 2000. But he’s made headlines recently by creating a couple of surprise expansions for Doom, and his forthcoming sci-fi blaster, Blackroom, is an object of much interest among patrons of the old school.

Facebook Twitter Pinterest Doom ... unashamedly abstract and filled with secrets. Photograph: id software

When I meet Romero after a media showing of Empire of Sin, his partner Brenda Romero’s Prohibition-era gangster game (hence the speakeasy), I’m eager for his thoughts on how today’s shooters differ from the pixelated provocateurs of the 1990s. His eyes brighten when I start talking about demons and power-ups.

Modern shooters are too close to fantasy role-playing games in how they shower you with new weapons from battle to battle, Romero suggests. This abundance of loot – which reflects how blockbuster games generally have become Netflix-style services, defined by an unrelenting roll-out of “content” – means you spend as much time comparing guns in menus as savouring their capabilities. It encourages you to think of each gun as essentially disposable, like an obsolete make of smartphone. “The more weapons you throw in there, the more you’re playing an inventory game.”

Romero contrasts this to the sparing design of the original Doom, which launched in 1993 with a grand total of eight guns. “For Doom, it was really important that every time you got a new weapon, it never made any previous weapons useless. That was a critical design characteristic. We’re going to add a new thing that can’t negate anything that came before. So how do you get the chaingun and not cancel out the pistol? It’s to do with how much ammo it eats, and how inaccurate it is over distance – the pistol eats less ammo and is extremely accurate at a distance.”

Doom is also a game that knows how to keep a secret. It isn’t just a firefight simulator but a treacherous, vaguely avant-garde work of 3D architecture. Its levels are mazes of hidden rooms and camouflaged doors that screech open behind you – sometimes revealing a pile of ammunition, sometimes disgorging enemies into areas you’ve cleared. Today’s shooters set less store by secret spaces, Romero says, because they cost so much to make. Where Wolfenstein 3D was created by a dozen people in a matter of months, the likes of this year’s Call of Duty: Modern Warfare is the work of hundreds, and cost tens of millions of dollars. This expense discourages designers from adding anything that isn’t absolutely essential.

Romero noticed this trend while designing 1996’s Quake, which featured more elaborate, polygon-based environments than Doom with richer, naturalistic lighting. “Doom was easy to make secret rooms for. You just drew a few lines and put a door there. It’s not even a minute. With Quake, it was a lot more work, because in Quake, every single room was made up of six planes – you have to put the floor in, the back wall, the ceiling. You have to add the light in and make sure it’s the right brightness, that it hits each corner of the room. It took a lot more work to build Quake levels, and it’s got worse from there. And because it takes so much longer, people just don’t want to do secret areas, because how many people are going to see them?”

Financial pressures aside, the decline of secret rooms in shooters also reflects the growing popularity of realistic settings where such spatial intrigues might look out of place. Even when set in make-believe places, today’s shooters favour a gritty, grounded aesthetic that leaves less room for experimental design. “Every shooter takes place in the world somewhere,” Romero says. “There’s nothing crazy, it’s not like going to Xen in Half-Life. They always look really nice, but the abstract level style – I don’t see that around as much.”

In setting their sights on realism, shooters have opened themselves up like never before to criticism of the politics of their representations. Doom was reviled in the press for glamorising violence, but its cartoon gore seems harmless alongside the apparent historical revisionism of Call of Duty in particular. The shooter will always be gaming’s most controversial genre, Romero comments. “It’s all about guns, and guns are the things that are killing everybody in the United States. It’s definitely the hot button genre. Other games like League of Legends or strategy sims, they’ll never be as controversial, because it’s not the same feeling. You’re not shooting people dead in first-person.”

If big budget game design has drifted away from Doom, the game’s many modders have kept the old id Software spirit alive. Fans have released thousands of custom Doom levels since 1993, ranging from unlicensed Batman adaptations to The Adventures of Square, which swaps Doom’s squalor for eye-popping rainbow hues. Romero has contributed a few mods of his own. Earlier this year he released Sigil, an unofficial Doom epilogue which ranks among his finest creations.

Facebook Twitter Pinterest Sigil ... John Romero’s epilogue to Doom. Photograph: id software

Sigil puts many of Romero’s claims about the strengths of 90s shooter design into practice. It is packed full of secret areas, and treats guns not just as weapons but ways of solving puzzles. Aside from slaying legions of hellspawn you’ll catch glimpses of the Evil Eye, an old Doom prop that was only used a couple of times in the original game. The Eye is now a switch – you can shoot it to activate mechanisms such as secret doors and sunken bridges. As you move from level to level, the Eye becomes harder and harder to discover: finding it often means resisting Romero’s sneaky efforts to lure you in a particular direction. This encourages you to think about Sigil not just as a player, but as a fellow game designer.

For Romero, Sigil demonstrates that the shooters of the 90s aren’t just worth returning to, but worth building on – an idea borne out by recent, retro-themed shooters like DUSK and Amid Evil, which offer up their own, devilish twists on Doom and Quake. “Stuff that could have been done 25 years ago but was never thought of, I did with Sigil. And it’s like, yeah, this is cool. It’d be cool if more shooters had this.”