Updating Retro Games Without Their Source Code Is As Difficult As You Think

Welcome back to this week's Remastered, featuring an interview with the developers behind a new update for cult classic retro RTS games Krush Kill ‘N Destroy Xtreme and Krush Kill ‘N Destroy 2: Krossfire's. I hope you enjoy it and consider subscribing to the newsletter for free! If you'd like to support independent games media, you can also donate to my Ko-fi.

Krush Kill ‘N Destroy Can't Be Killed

When no one has access to the source code for a retro game, re-releasing it and keeping its modern version consistently updated becomes significantly harder. I first encountered this harsh reality when interviewing Mega Cat Studios about Backyard Baseball's revival for Save State in 2024. Now, I have encountered it again after speaking with the developers behind a new update for the Steam and GOG versions of Krush Kill ‘N Destroy Xtreme and Krush Kill ‘N Destroy 2: Krossfire.

Krush Kill ‘N Destroy (which I will refer to as KKND from here on out) is a cult-classic series of post-apocalyptic real-time strategy games with silly FMVs. To relate it to other games of its era, it's essentially Command & Conquer meets Fallout. In 2020, Ziggurat re-released the two KKND games on Steam. Six years later, Ziggurat is adding features like online multiplayer to these nearly 30-year-old RTS games with the help of some hard-working modders.

While everything Ziggurat is adding to, and improving within, both KKND games is impressive, it was still surprising to hear modder and developer Andre Mohren admit, "I hope people don't imagine more into the patch than has been announced." Because of our conversation about this patch's comprehensive development, that sentiment became a little easier to understand.

15 years ago, KKND fan Andre Mohren and his friend Johannes Wüller wanted to mod these underappreciated RTS games to fix a visual issue. There was just one problem: there weren't any modding tools. KKND's under-the-radar status meant it didn't proliferate a franchise in quite the same way as Command & Conquer or Starcraft. That left a lot of room for Mohren and Wüller to explore as programmers, and they became some of the premier modders working on KKND.

Following the Steam release of the KKND titles in 2020, Mohren reached out to Ziggurat and found the company eager to update these retro games. Producer Alex Lotz tells me Ziggurat appreciates KKND's "playfulness" and the game’s "international appeal and connectedness" with passionate fans despite its relative obscurity. From there, a partnership working on this ambitious update could begin.

The KKND games' Steam re-releases were already somewhat imperfect because of the lack of source code. When you buy the game on Steam, you're essentially playing a ROM-hacked version of the original disc version, tailored to work better on modern PCs. While Ziggurat is in contact with some of the original developers, the source code remains missing. And as Mohren and Wüller go into the game to make even more substantial changes, the challenges of working without source code continue to rear their head. 

"It's a real mess… You just have memory addresses and weird CPU opcodes [operation codes] which do things. I mean, I'm a 20-year professional developer, and I never did such a hard thing ever," Mohren told me. He also went into detail about the copy protections put in the games by the original developers, and how those tools introduced random issues and "explicitly broken CPU opcodes" that make loading the games into a disassembler and modifying them even harder.

It took Mohren just five months to reverse-engineer and extract sound assets from the KKND games. After all of that hard work, Mohren has been able to create an SDK library and tool that is "able to decompile any game assets and also recompile them into a 100% equal binary." The existence of that tool will make KKND more modder-friendly after the June update, as modders will be able to add their own sprites and sounds to these old RTS games.

Even more impressive is online multiplayer, which is often dreadfully complicated to set up on retro PC games built for LAN rather than online play. Multiplayer is Wüller's domain, though he had to deal with the fact that the KKND games used DirectPlay, a Microsoft networking API that's no longer supported. Wüller explained exactly what he has had to do to get online multiplayer working properly:

"What we're doing is essentially replacing the broken networking stuff and patching in our own path into the networking stack so we can put stuff in like Steam lobbying and matchmaking. We've also fixed some issues with TCP/IP [its internet protocol suite] and a couple of other things that were actually broken in the original that no one seems to have noticed…We've basically gone and figured out everything the game asks DirectPlay to do, and then we go in and kind of substitute our own at that point." 

I'm not aware of any retro release without source code that does this, and neither is Wüller, who hopes his work here can be used to restore online multiplayer for other DirectPlay games in the future.

All of this is only something you'd do if you are truly passionate about the short-lived series, and Mohren and Wüller truly are. Mohren remembers discovering KKND in the German gaming magazine GameStar and playing the games with his father as a kid. KKND is also at the center of Wüller's and Mohren's friendship now, as modding the game has brought the pair close over the past 15 years, as they work to improve it between their day jobs.

Still, some things can't be done without the source code. That includes Steam achievements, which Mohren tells me require the "whole game executable" to function properly with the Steam API, something that's just not possible right now. While Lotz expressed interest in eventually adding achievement support and Trading Cards on Steam, it's not something players should expect soon.

Not being able to kick players from multiplayer lobbies and desync issues caused by custom levels with the same name are also problems this update won't fix. Don't expect the AI or UI in these KKND games to radically improve either. "We can't really make new user interface tweaks or stuff like that right now," Wüller explained. "We can make behavioral tweaks, but it's not necessarily possible yet to make entirely new features. We can adjust what exists, basically, for now." 

Ziggurat producer Alex Lotz hopes this re-release not only pleases and excites KKND fans, but that their work and struggles can inspire developers to be more preservation-minded with any source code for classic games that they have access to. 

“For a long time, people have thought of video games as ephemera, where they're working on this product to get the product out and move on to the next thing. Now, I think we have a better understanding that there's cultural and historical significance to these games, and it's worth preserving, at the very least, the source code."

Despite the restrictions and challenges these modders-turned-game-devs continue to face in updating these old games, the work feels worth it. Stable online multiplayer, the innumerable bug fixes, support for higher resolutions, and the additional languages added through this update will make these versions of KKND the definitive releases for this series once the patch rolls out. 

Expect the Steam versions of Krush Kill ‘N Destroy Xtreme and Krush Kill ‘N Destroy 2: Krossfire to be updated sometime this June, although those who own the games can opt into a closed beta test beforehand.

What's Old Is News

Teased retro revivals, retiring developers, and more

• Capcom's latest financial report once again hints that it wants to revitalize older IPs like Ace Attorney, Mega Man, Dragon's Dogma, Dead Rising, Okami, and Devil May Cry. Some of these have announced new games, others don't. 
• Sega canceled its mysterious “Super Game”, Game File reports. Thankfully, new Crazy Taxi, Streets of Rage, Golden Axe, and Jet Set Radio games are still in the works.
• Tekken Boss Katsuhiro Harada defected from Bandai Namco to start VS Studio with SNK. We don't yet know if he'll be working on legacy retro IP, or something brand new, Game Informer reports.
• The excellent Myst and Riven remakes are coming to consoles, but Riven's accompanying physical soundtrack release is unfortunately embroiled in a controversy over its use of generative AI to create an image.
• Legendary Nintendo developer Takashi Tezuka is retiring next month. 
• The PS1 version of Time Crisis is coming to the PlayStation Plus Premium's Classics catalog on May 19, with gyro aiming support.

There has been a lot of annoying online discourse about Mixtape. I'm here to throw my hat into the ring and say…

• Mixtape: It's fine! I'm not a particularly music-savvy person, nor was I very rebellious as a teenager, so Mixtape didn't quite speak to me on a deeper level like it has for many other critics. That said, I can still respect its slick presentation, its American Graffiti-like story for 90s kids, and the amazing soundtrack curated by Beethoven & Dinosaur. If you're subscribed to this newsletter because you're nostalgic for older media, you'll likely find a lot to love about Mixtape. It won't be topping my personal game of the year list, but I can heartily recommend it to anyone with a passion for older music, dare I say, “retro” songs.
• Gamble With Your Friends: It's not retro-related at all, but for Polygon, I wrote about this new viral friendslop game. Its million-selling success is certainly interesting, given that gambling is drawing attention away from the gaming industry right now. Maybe there's a deeper reason games like this and Balatro are resonating with people so much.

Thanks for reading all of the way through Remastered this week! I really appreciate it! In the lead-up to Summer Game Fest, which I will be attending next month, I hope you consider subscribing if you aren't already or supporting me on Ko-fi.