My five-year-old has been trying out some of my favourite video games this year, and I’ll admit some of them are not exactly age-appropriate. But his favourite by a mile is the original DOOM on easy mode. The simple controls mean he can actually keep up, and the aged graphics just read as Minecraft to him rather than anything gorier. I’ve also been letting him loose on TimeSplitters 2’s custom level builder and its custom match types, building him silly bot matches he can win, bot matches for now anyway, since I’ve misplaced my other two PS5 controllers. It was actually a conversation with a friend about that, and mentioning TimeSplitters 2 is now on PS5, that got us talking about how I’d bought Homefront: The Revolution a few years ago specifically because of the discovered TimeSplitters 2 Easter egg inside it. One thing led to another, and here we are.
Because buried inside plenty of the biggest games ever made is a second, completely different game, sitting there waiting for someone patient enough to find it. It’s one of gaming’s oldest traditions, and it’s also one of the best arguments for actually finishing a game instead of trading it in the moment the credits roll. These aren’t cut-down demos or teaser snippets either, for the most part they’re genuinely complete games you can play start to finish, smuggled in as a reward for people who bother to look. On older cartridge-based systems, everyone had been fighting to squeeze their game into the limited space available. The trend really picked up once games moved onto CDs and DVDs and that problem flipped entirely, developers suddenly had far more disc space than their games actually needed and started having a bit of fun with what was left over. Here they are, roughly in the order the trend actually grew, from an 80s console quirk through to whatever Doom decides to do next.
The Sega Master System Hides a Maze Game in Its Startup Screen
This is the oldest trick on the list, and easily the smallest in scope. Later Master System revisions built in Alex Kidd in Miracle World or Sonic the Hedgehog as an advertised, official pack-in game you could boot straight into, no cartridge needed. That’s not what’s going on here. Early Master System consoles had no built-in game to speak of, just instructions on screen for inserting a cartridge, and yet a game called Snail Maze was hidden inside the BIOS anyway. Hold up plus buttons 1 and 2 together while the Master System’s startup screen is loading and Snail Maze boots up on its own, a genuine secret nobody at Sega ever put on the box. The only way most people found out about it at the time was by mailing in their warranty card, since Sega tucked the unlock code into the hints section of the Sega Challenge newsletter it sent back to registered owners.
Day of the Tentacle Contains the Entire Original Maniac Mansion
LucasArts did this one first and arguably did it best. Day of the Tentacle was the sequel to Maniac Mansion, and rather than just referencing the original game, the developers built the whole thing into it. Walk into Ed’s bedroom as Bernard and you can boot up his computer to find a completely playable copy of Maniac Mansion running start to finish, puzzles and all. It’s one of the earliest examples of a full game hidden inside another one, and it set the template every entry on this list has been chasing since.
Donkey Kong 64 Hides the Original Donkey Kong Arcade Game
This is the one that started the conversation with my kid, and it’s a genuinely good pub trivia answer. Once Donkey Kong learns his Gorilla Grab move in Frantic Factory, you can pull the lever on the arcade cabinet sitting in the level and play a full port of the original 1981 Donkey Kong arcade game. Beat it once for a Golden Banana, then beat it again for the Nintendo Coin, one of the items required to complete the game. Collect fifteen Banana Medals and Cranky Kong also gives you a single stage of Jetpac, Rare’s own 1983 shooter, for the Rareware Coin. It’s a trimmed slice rather than the full arcade release, but it felt wrong not to mention it too.
Animal Crossing Lets You Unlock Actual NES Games to Play in Your House
Animal Crossing on the GameCube buried a genuinely generous secret in its furniture system. Find and place an NES console in your house and you can unlock and play full original NES games right there on your TV inside the game. In total there were 19 of them built into the Western release, including Donkey Kong, Donkey Kong Jr., Donkey Kong Jr. Math, Donkey Kong 3, Balloon Fight, Clu Clu Land, Golf, Tennis, Pinball, Soccer, Excitebike, Baseball, Punch-Out!! Featuring Mr. Dream and Wario’s Woods. Most of these turned up through Tom Nook’s shop, random digging, or trading with villagers, all part of the normal daily grind of the game. Four of them, nicknamed the “Forbidden Four” by fans, needed Nintendo of America’s e-Reader card giveaways instead: Ice Climber, Mario Bros., Super Mario Bros. and The Legend of Zelda.
Project Gotham Racing Hides an Entire Different Genre in Its Garage
This is the strangest one on the list, because the hidden game went on to outlive the game hiding it. Tucked in the back of the garage in Project Gotham Racing is an arcade cabinet for Geometry Wars, a retro-styled twin-stick space shooter that most players never noticed. It proved so popular that Geometry Wars became its own franchise, with Geometry Wars 2 going on to become one of the most downloaded games on Xbox Live Arcade. Not bad for something that started life as a bonus nobody asked for.
Metroid Prime and Metroid: Zero Mission Both Unlock the Original 1986 Metroid
Nintendo did this twice within a couple of years of each other, using two completely different methods. Metroid Prime does it the hard way. Connect a Game Boy Advance running Metroid Fusion to your GameCube with the official link cable and Prime unlocks the original 1986 Metroid to play in full, which is a ridiculous amount of extra hardware to track down for one Easter egg. Metroid: Zero Mission does it the easy way. Finish Nintendo’s Game Boy Advance remake and you unlock an emulated version of the same original NES game as a straightforward completion bonus, no cables or spare consoles required. Between the two, it’s a small thing, but it turns both remakes into a proper history lesson, and it’s one of the more generous unlockables on this list either way.
Pitfall: The Lost Expedition Hides Two Entire Atari Classics
I remember reading about this one in a magazine years ago, though with a GameCube collection as large as mine that I haven’t properly gone through in years, I honestly can’t say for certain whether The Lost Expedition is sitting in there somewhere or not. Finish the game and knock over some achievements, and you unlock the original Pitfall! and Pitfall II: The Lost Caverns, both playable in full exactly as they ran on the Atari 2600. It’s a nice bit of respect for a franchise most modern players have never actually touched, and it’s the kind of Easter egg that only really survives in magazine trivia pages, articles like this one, and maybe a dusty case somewhere in my own collection.
Star Fox: Assault Hides a Full Port of the Arcade Shooter Xevious
You’d probably assume the hidden game in a Star Fox title would be the original SNES Star Fox or N64 Star Fox 64, but Assault couldn’t pull that off, since it wasn’t made by Nintendo EAD like those two, it was developed by Namco instead. What Namco snuck in was one of their own games. Track down the unlockable and you get a full port of Xevious, Namco’s own 1983 shoot ’em up, playable start to finish. The Japanese release went even further, throwing in two extra Famicom titles, the space shooter Star Luster and the tank game Battle City, alongside Xevious. It’s the kind of extra that makes a lesser series entry worth revisiting.
Castlevania: Dracula X Chronicles Hides All of Symphony of the Night
Dracula X Chronicles is Konami’s 2007 PSP remake of Rondo of Blood, a game most Western players never actually had the chance to play, since it was originally a PC Engine release that stayed in Japan back in 1993. The remake rebuilt it in 3D for a whole new audience, and the developers went further than a straight remake. Play through to around the third or fourth level and grab a specific hidden pickup, and you unlock a full port of Symphony of the Night, widely considered one of the best games in the entire series, sitting there as a bonus inside a remake of a completely different entry.
Contra 4 Unlocks the Original Contra and Super C in Full
Konami didn’t hold back with this one. Beat four challenges in Contra 4’s Challenge Mode and you unlock the entire original NES Contra. Beat eight and you get its sequel, Super C, as well, both fully playable exactly as they ran in 1988 and 1990. Two entire classic games handed over for a handful of side challenges is generous even by the standards of this list.
Call of Duty: Black Ops Hides Zork and a Full Arcade Shooter in the Main Menu
Not every hidden game needs a boss fight to unlock it. In Call of Duty: Black Ops, interact with the computer terminal on the main menu and type “Zork” to load up a working version of the 1980s text adventure Zork. Keep poking around the same terminal and you’ll also stumble onto Dead Ops Arcade, a full top-down twin-stick shooter that has nothing to do with the rest of the game and is oddly one of the better zombie survival modes Treyarch has made.
Homefront: The Revolution Accidentally Shipped With the Entire TimeSplitters 2
This is the best hidden game story going, mostly because nobody meant for it to happen. Homefront: The Revolution always had two playable levels of TimeSplitters 2 tucked into a worn-out arcade cabinet in the Bourse hideout, found partway through the mission “Small By Name”. What nobody knew until 2021 was that developer Dambuster Studios, formerly Free Radical Design, the actual team behind TimeSplitters 2, had ported the complete game into Homefront’s code as the easiest way to build that demo, then locked the rest behind a code nobody wrote down. A former developer mentioned it in a throwaway tweet, a notebook with the unlock sequence had gone missing, and it took a principal engineer at Xbox digging through his own memory to recover the actual code five years after the game shipped.
TimeSplitters 2 on the GameCube was one of my favourite games growing up, so once the code went public I bought Homefront a few years ago purely to get my hands on it again. Punch the code into the Extras menu once you’ve found the cabinet and you get the whole thing running in native 4K on hardware it was never designed for. These days you don’t even need the workaround. The entire TimeSplitters trilogy, not just TimeSplitters 2, got an official PS4 and PS5 re-release in 2024 as part of a PS2 Classics push, and it’s now the game I get to hand my own kid a controller for.
Fittingly, TimeSplitters 2 has its own hidden game buried inside it too. Find a cartridge called Anaconda on a shelf in the Siberia level and you unlock a Snake-style game you can play any time through your Temporal Uplink, with a four player competitive mode, and a piece of chiptune music that has lived in my head rent free since I was a teenager. It might be the catchiest thing Free Radical ever wrote, and that’s including the actual TimeSplitters soundtrack.
Hitman (2016) Hides Minesweeper Behind One of the Strangest Unlock Conditions Going
This one deserves a mention purely for how absurd the requirements are. Somewhere in Hitman’s Paris level sits a working copy of Minesweeper, and to unlock it you need to find an exploding rubber duck and place it under a specific pole in the level. Nobody has ever explained why, and honestly, that’s part of the fun.
Early Nintendo Switch Consoles Hid an Inferred Tribute to Satoru Iwata
Like Snail Maze on the Master System, this one isn’t hidden inside a game at all, it’s hidden inside the console itself. Early Switch firmware carried a fully playable version of the NES game Golf, a game the late Nintendo president Satoru Iwata had personally programmed decades earlier. To unlock it, you had to set the console’s date to 11 July, the day Iwata passed away in 2015, then perform a specific Joy-Con gesture resembling his trademark Nintendo Direct greeting, which triggered a short voice sample of Iwata before the game appeared. This was never something Nintendo promoted or acknowledged officially, and it was likely slipped in quietly by someone on the development team as a personal tribute rather than a sanctioned company decision, which would explain why it was later patched out of the firmware entirely. Unless you had a launch Switch that never went online before that update, it’s effectively gone now.
Celeste Hides the Original Pico-8 Prototype It Grew From
Celeste started life as a tiny game made in four days for a game jam, built using Pico-8, a stripped-down game engine designed to mimic the limitations of an old console without ever being real hardware. The full commercial release never buried that history, it built it in. Find the computer room in Chapter 3 of Celeste and you can boot up that original Pico-8 version from the main menu, playable in full, pixels and all. It’s a nice way of letting players see exactly where the finished game came from.
Wolfenstein: Youngblood Hides a Sequel to an Easter Egg From the Previous Game
Rather than dropping in the actual 1992 Wolfenstein 3D, MachineGames built its own alternate-history version and has kept building on it. Wolfenstein II: The New Colossus first introduced Wolfstone 3D: Elite Hans, an arcade cabinet swapping B.J. Blazkowicz for a Nazi antagonist called Elite Hans. Youngblood then went a step further with a genuine sequel, Elite Hans 2: Die Neue Ordnung, a fully playable game start to finish, not a demo, complete with its own save file on the cabinet between missions. Neither version has ever been sold on its own. They only exist as arcade cabinets inside the two games that hide them.
MediEvil’s 2019 Remake Hides the Original 1998 Game in Full
Sony’s remake of MediEvil didn’t just modernise Sir Daniel Fortesque, it kept the original underneath. Complete all nineteen Lost Souls objectives scattered through the remake’s levels and you unlock the entire 1998 original from the main menu, playable start to finish exactly as it shipped on PS1.
Doom Eternal Gives You the Original Doom and Doom 2 as a Reward
This is the modern version of the same idea, and it’s genuinely satisfying to unlock. Beat the final boss of Doom Eternal and clean up the collectibles scattered through the campaign, and you’re rewarded with fully playable versions of the original Doom and Doom 2 sitting on the computer in your hub world. Realistically, anyone buying Doom Eternal already owns Doom and Doom 2 on a dozen formats between old CD-ROMs, Steam bundles and phone ports, so it’s not exactly a lost classic being unearthed. But if you somehow don’t, it’s free extra playtime tacked onto your purchase, and it’s a genuinely thoughtful way to close the loop on a series that’s been going since 1993.
Yakuza Games Let You Play Entire, Real Sega Arcade Classics Inside Their Arcades
The Yakuza series does this one properly and does it often. Walk into any in-game arcade across the series and you’re not looking at a mocked-up cabinet with a logo slapped on it, you’re getting fully licensed, fully playable ports of actual Sega classics like Space Harrier, OutRun and Fantasy Zone, sitting there as a distraction from the main crime story. It makes sense once you remember who publishes the series. Sega owns its own back catalogue outright, so rather than building fake arcade games from scratch, it was easier to just drop the real ones in.
High on Life and Its Sequel Both Hide Full, Real Movies to Watch
High on Life, released in 2022, bought the actual rights to four real B-movies: the cult schlock horror Tammy and the T-Rex, Blood Harvest, Vampire Hookers, and Demon Wind, and lets you watch them start to finish, either on the TV in Gene’s house or in a secret in-game cinema you unlock later. It even comes with an achievement called “We Paid for the Rights to Put a Whole Movie,” which is a pretty honest way to describe it. High on Life 2, released in February 2026, kept the tradition going with its own venue, the Krust Theatre, offering five more full films: Manborg, Spookies, New York Ninja, Blood Tracks and Don’t Open Till Christmas, with a sixth poster on the wall that stays locked until you’ve finished a certain story mission.
FAQ
Why do developers hide entire games inside their games? Mostly love of the medium. It started as an in-joke among developers referencing their own back catalogue, and it’s stuck around because players genuinely enjoy finding it. It also doubles as quiet game preservation, keeping older titles playable on modern hardware without a separate re-release.
What other things do developers hide in games besides other games? A couple of cool examples: The Witcher 3 buried an entire card game called Gwent as an optional distraction, and it proved so popular it spun off into its own standalone game, Gwent: The Witcher Card Game, much like Geometry Wars did after Project Gotham Racing. Red Dead Redemption 2 went a different direction, building fully functional versions of real card and dice games like poker, blackjack and dominoes that you can sit down and play start to finish around a campfire, rather than a simplified minigame version of them.
Do developers ever include hidden games by accident? Occasionally, and Homefront: The Revolution is the best documented case of it. The full TimeSplitters 2 port was built for practical development reasons rather than as a deliberate Easter egg, and the unlock code was nearly lost for good before someone remembered it years later.
Do newer games still do this, or is it a dying tradition? It’s rarer than it used to be, mostly because publishers have realised people will pay for those old games separately. Most of the examples on this list come from before consoles could easily download older titles on their own, back when a re-release as a standalone purchase wasn’t really an option outside the odd anthology collection. Sony’s built an entire standalone business around this now, with over a hundred PS1, PS2 and PSP classics available to buy individually on the PlayStation Store or through the PS Plus Premium classics catalogue, rather than making players hunt for them inside newer games. Microsoft has leaned the same way with Nintendo Switch Online. But the hidden game trend hasn’t disappeared entirely. Doom Eternal proved as recently as 2020 that a well-placed hidden game still makes headlines.
