Bloody ludicrous: The making of Turbo Overkill, 2023's most outrageous shooter

If ever a game lived up to its title, it’s Turbo Overkill. A cyberpunk retro shooter about a cigar-smoking cyborg with a chainsaw installed in his leg, Turbo Overkill starts with you carving up the minions of a rogue AI in a neon-drenched metropolis, and ends with you battling digital demigods in outer space.

The game’s 15 weapons range from a sniper rifle that can teleport the player into enemy bodies to a target-painting system for an orbital bombardment platform. It lets you fly a weaponized hovercar, ride a motorcycle through an irradiated wasteland, and even pilot a mech across the hull of a starship. When the final version burst from Early Access this August, the most notable criticism Turbo Overkill received was that it had too much going on.

Turbo Overkill is comfortably the best shooter of 2023, and possibly the best game to emerge from the entire retro shooter revival. But what's most remarkable about it isn't the game's absurd scope, wild variety, or in-your-face attitude. It's the fact that virtually everything in it was made by just one person.

"It's kind of daunting when I look back on the game now and look at how much stuff is in there," says Sam Prebble, Turbo Overkill's designer. "If you were to follow the Early Access and play it episode by episode, it does definitely feel like three to four games."

Ever since I learned Turbo Overkill was a solo project, I've been desperate to know how Prebble pulled it off. The full story is a decades-long tale of obsession with, dedication to, and mastery of first-person shooter design.

The short version is summarized by Apogee's Scott Miller, Turbo Overkill's publisher. "I've worked with some very talented people," says Miller, whose associates include the designers of Doom, Max Payne, and Duke Nukem 3D, "But I've honestly never met anyone as talented as Sam across the board."

The story begins, fittingly enough, with an Apogee-published game—1993's Monster Bash, the first game Sam Prebble remembers playing. "I took a lot of cues from my brother, who's four years older than me. He used to download stuff online all the time. He was quite familiar with the whole shareware scene."

Prebble doesn't recall many specifics about the anarchic side-scrolling platformer, except to say it "had a really big effect on me." But the next game he played stuck with him for almost 30 years—id Software's Doom.

"I was playing Doom, like the shareware version of Doom, back when I was about five or six years old," Prebble says. And he didn't just play it, he feasted upon it. "It was probably the only game I ever really played." When he finally put Doom aside, it was only to pick up the sequel, which he received as a Christmas present. "I knew I was getting it for Christmas," he says. "I was so excited that I opened it before it was Christmas."

Yet while Prebble was fascinated with Doom from a very early age, it wasn't playing the game that would ultimately define his future. "When I figured out you could make your own levels for it, I just lost my mind."

At seven years old, Prebble began making custom maps and missions for Doom (known as WADs after their .wad file format, an acronym for "Where's All the Data?"). "They're pretty bad maps," Prebble says about his preposterously early work.

Nonetheless, he began uploading his creations to websites like Doom Wad Station, founded in 1998 and one of the earliest Doom modding sites. "I got quite involved with the communities like Doomworld and the Skulltag community, releasing maps there," he adds.

Many of Prebble's early maps involved mixing Doom with other shooters like Unreal Tournament and Halo. But as his familiarity with Doom modding grew, so did his ambitions. In 2009, he released Shotgun Frenzy, a multiplayer "Invasion"-style mod that saw players band together to hold off huge waves of enemies. It introduced numerous new mechanics into Doom, including base-building, tech-researching, and deployable weapons like turrets.

By the time Shotgun Frenzy released, Prebble wanted to build his own creations out of Doom's modding tool. "In my teens, I was more interested in total conversions. Basically, you make a Doom mod and you replace all of the graphics and all of the sprites with completely original content."

In 2008, Prebble began concepting Total Chaos, a hugely ambitious mod for Doom II that transforms it into a grim, austere survival horror game complete with full 3D graphics, unique art, models, and sounds. "I used that as a platform to teach myself how to make video games," says Prebble.

At this point, Prebble knew he wanted to make games professionally. But Prebble lives in New Zealand, and in the late 2000s, the country's games industry was still nascent.
Instead, Prebble ended up working in TV, initially designing motion graphics for children's shows. The same year he began work on Total Chaos, Prebble joined renowned visual effects studio Weta Digital, where he worked on his first major media project, James Cameron's Avatar.

"Weta Digital was great, because I learned a lot about asset pipelines and how to properly make 3D models." Prebble would later apply those skills to both Total Chaos and Turbo Overkill, with his film background especially visible in the latter's cinematic first-person cutscenes.

Prebble did eventually join the games industry, joining forces with several other Weta Digital employees to form the studio A44. There, he worked for three years on the Soulslike Ashen. But he really wanted to focus on his own projects. "I left A44 and went to do my own thing again until I ran out of savings."

Yet after releasing Total Chaos in 2018—10 years after he'd first conceived the project, and six years after commencing development—Prebble wasn't sure what that next thing should be. He wanted to make a shooter, and he wanted it to be a commercial endeavor. Beyond that, he struggled with ideas. His first attempt at a new project was "a demon hellscape sort of thing," but he quickly realized he was basically making Doom. "I was like 'This has been done a million times.'"

Ironically, Prebble's inspiration for Turbo Overkill came not from an old shooter, but from a new one. "I was playing a lot of Apex Legends at the time, and I really enjoyed the sliding mechanics," he says. "I was like, 'What if sliding into enemies killed them?'"

Prebble put together a prototype and enjoyed it, but figured players would need a visual reference to explain why sliding into enemies dealt so much damage. "I was like 'Ah, let's put a chainsaw in there,’" he says. "The whole cyberpunk thing came from that."

Everything in Turbo Overkill was built outward from the chainsaw-slide. Prebble took the theme of cybernetic augmentation and extended it to the cyberpunk aesthetic, combining the ‘80s stylings of Blade Runner (for the general cityscape) with the body horror of Akira (the game’s twisted cyborg enemies and subterranean flesh warrens).

The weapon roster emphasized hybridisation as well, bringing together wildly divergent fire-modes to create multifunctional tools. "I wanted them to be quite out there," says Prebble. “I also wanted to streamline a lot of stuff…like okay, you can either have a shotgun and a grenade launcher as separate weapons, or you can just combine them."

Prebble had a working build of Turbo Overkill's first episode within a year, but he says it "wasn't actually that fun". Fortunately, finding the fun is what Prebble enjoys most about game development. "I love working on something for a day and seeing the result of it working the way I imagined it would. It's a lot of persistence, just being patient with it."

The game's lo-fi visuals also let him focus on building levels and refining the play experience. Or as he puts it, "I could get away with a lot of nasty graphics.”

By April 2021, Prebble was confident enough in Turbo Overkill to put a gameplay reveal on YouTube. To date, the video has accrued 90,000 views, which isn't a huge number by YouTube standards—but it was big enough. One of the people who saw the reveal was Scott Miller, who had recently restarted the Apogee publishing label with its current license holder, Terry Nagy.

"[Nagy] approached me and said 'Hey, I have the rights to this name, and you're not working with 3D Realms anymore, do you want to reboot Apogee?" says Miller. "I didn't even hesitate. I said. 'Yeah, let's do it.'"

Miller wanted the reborn Apogee to be "An indie publisher, way under the radar,” and had signed several smaller games when he stumbled upon Turbo Overkill's gameplay reveal. "I was like, damn, this thing has a little magic to it," Miller says. Turbo Overkill reminded him of seeing Wolfenstein 3D for the first time, which Apogee published back in 1992. "I always tell people, luck is such a big part of anyone's success," he says. "I was at the right place at the right time to meet the founders of id Software…and it's the same thing connecting with Sam. It's just right place, right time."

According to Miller, it took "several months" to put together a deal, but ultimately it was swung by Prebble's personal history with Apogee. In a weird coincidence, Prebble had previously seen that Apogee was back in business and, thinking about his days playing Monster Bash as a kid, he’d emailed the company to see if they were interested in publishing Turbo Overkill.

It isn't wholly clear how much of a hand Miller and Apogee had in Turbo Overkill's design. Apogee took the lead on the game's soundtrack, the one part of the game Prebble definitely didn't create. "I don't do music," he says. But with most everything else, Miller insists that Apogee were completely hands off, stating that Prebble is a "one-man show". Prebble, however, says that Miller is being humble. "He had a lot of great ideas that made Turbo Overkill what it is."

Certainly, Apogee didn't hold Prebble back in any way, even as his ambitions grew over the course of development. The first episode released into Early Access in April 2022, whereupon Turbo Overkill received a lot of positive feedback for its seventh mission, Rooftops. The expansive mission lets players drive a hovercar around an open area containing multiple skyscrapers, jumping in and out of the vehicle to battle enemies. "After that vehicle level, I mandated myself to have one vehicle level per episode," Prebble explains.

Around this time, the 2001 build for the long-delayed Duke Nukem Forever leaked online, and it included a level where Duke rides a motorbike. "I was like 'That looks really cool, I want to steal that,'" Prebble says.

The resulting level, simply titled Exodus, is a 30-minute chase sequence where Turbo Overkill’s protagonist, Johnny Turbo, races to escape from the hedonistic city of Paradise while the rogue AI Syn shoots lasers from a giant Eye of Sauron-style tower. It was by far the most ambitious level Prebble had designed.

Sadly, it also sucked. "The original level for that was pretty awful," says Prebble. It turned out a motorbike was extremely difficult to work into a first-person shooter. "They're awful to control," Prebble continues. "You go from being this juggernaut jumping around killing everything very fast, and then suddenly you're locked in on a bike."

Fortunately, Prebble's love of finding the fun kicked in, and he completely redesigned the level for the game's final release, turning the motorcycle into a hoverbike that used the same programming logic of Episode One's hovercar. "I learned a lot making that level," Prebble says.

By Episode Three's development, Prebble's creativity was in overdrive. The levels he'd designed thus far were already elaborate for a retro shooter, with even the shorter maps taking around 25 minutes to complete. By Episode Three, some levels were approaching 45 minutes in length.

No single mission epitomizes the growth of Prebble's ambition more than Terminal Eclipse, which sees Johnny fight through the inside and outside of multiple spaceships against the backdrop of a vast battle in Earth orbit. Culminating with an extended mech sequence, Terminal Eclipse would be impressive even coming from a studio with much greater resources.

"I always knew from the beginning that I wanted to do an insane space level," says Prebble. "The problem is, I have these really ambitious ideas, but trying to pull them off can be quite challenging. There was a lot of experimentation."

There was also a lot of graft. At the start of development, Prebble could average a level a week. But by Episode Three, each level took a month to develop. "It gets bloody ludicrous," he says. "There were times by the end of it where I did feel quite burnt out on the project."

Turbo Overkill had developed a strong reputation among fans of retro shooters during its Early Access phase. The final release only enhanced its reputation, though a few critics thought it took the "overkill" part of its name too literally. "Most of the reviews were really good, but a few criticisms were [that] the game was too long," Prebble says.

Miller was delighted by the game's reception. "For us, it's been an outstanding release," he says. "Sold really well, it continues to sell, and the reviews are outstanding."

For the man who founded Apogee, and the man who started life playing Apogee games, the journey isn't over. They're currently working on console ports of Turbo Overkill, but there are bigger plans as well. "At some point, we're going to start working on a new game, probably [at] the beginning of next year," Miller says. He doesn't confirm exactly what the game will be, but he does say this: "At the end of [Turbo Overkill], you see the words 'Johnny will return.’ That's definitely in the plans."

Making a sequel to Turbo Overkill would be a tall order, but Prebble's own skills have grown through developing the original. "I've learned a lot from it. It's been very energizing." Besides, sequels are all about escalation—and if there's one thing Turbo Overkill proves, it's that Prebble knows how to take things to the next level.

You can pick up Turbo Overkill now on the Epic Games Store.