Retro gamers love going back and checking out their favorite classic games. There's something about those old 2D platformers and JRPGs that modern games haven't really matched. And classic games are even more fun to enjoy with friends. There are plenty of classic multiplayer games to choose from, like Bubble Bobble to Mario Kart 64 and Crash Team Racing. Unfortunately, not every great classic has multiplayer, meaning groups of gamers are sometimes relegated to taking turns or simply watching their one friend beat The Legend of Zelda: Ocarina of Time for the 20th time.

Fortunately in this modern digital age, many likeminded fans of retro games have used their creative skills and programming knowledge to turn their favorite single-player childhood games into multiplayer experiences. Today we're going to be taking a look at several mods and ROM hacks that takes games such as DuckTales, Super Metroid and Super Mario 64, and makes them playable for two, foꦓur, or even eight or more players.

As an added bonus, we'll also be taking a look at several games tha🌳t had secret multiplayer modes hidden inside the base game all along, some of whi🥀ch weren't even discovered until years later when people started emulating games.

And if you do want to try your hand at some of these variations on old classics with your friends, you'd better act quick.🎃 Given that a majority of these modified classics are Nintendo games and the Big N isn't very fond of fan games, don't expect these ROM hacks to be available for very long.

20 The Mystery Of Hangar 96 𓃲

via: YouTube (MyChemicalBromance)

Long before Bungie Software was revolutionizing first-person shooters on consoles with Halo, they had the Marathon Trilogy, a series of FPS games released on the PC in the nineties. Like many PC shꩲooters, online multiplayer was a🐲 big draw, and each game had plenty of maps to choose from.

But there was one map hidden in the code of Marathon Infinity called "Hangar 96." M๊ost gamers didn't even know about this map, given that Hangar 96 was only referenced in the three dream levels of the game. Grainy pictures of the map can be found in each level. Event🍎ually, some clever players noticed that if you combine the hexadecimal codes found in the first and last levels terminal, it would create a map called "Hats off to Eight Nineteen," which matches the grainy pictures of Hangar 96.

19 Dibs On Sean Connery 🌟

via: goldeneyevault.com

GoldenEye 007 managed to not only be incredibly successful, but make first-person shooters a popular console genre. The single-player campaign was good, but what really made it stand out was the multiplayer, with different game types such as standard deathmatch to The Living Daylights and Licence to Kill.

Of course, what great game couldn't be improved with a little modding? Once people started releasing ROMs of Nintendo 64 titles, a hack for GoldenEye was released which included an "All Bonds" mode, which allows gamers to play as either Sean Connery, Roger Moore, Timothy Dalton or Pierce Brosnan in multiplayer. Interestingly enough, this mod doesn't actually add anything to the game. It turns out Rare meant to include this as a feature in the original releas🍌e of the game, but removed it (probably due to not being able to use the other actors' likenesses). Time to pick your favorite Bond.

18 💦 💎 Double The Action

via: YouTube (Arcade Database)

Back in the eighties, SNK was a big name in the arcade scene, releasing such classics as Athena, Ikari Warriors and P.O.W.: Prisoners of War. Many of these titles were playable with two people which only made them even more popular at the time. P.O.W. was so popular, in fact, that it even saw a port to the NES. While the port retains much of the same Rambo-inspired beat 'em up action, iඣt does have one major drawback: single-player only.

Fast-forward to today, and someone finally added to this underrated NES classic. Now you m🌞ay be wondering, "if the arcade version already has 2-player mode, why not just download that ROM?" As great as that version was, there are certain changes in the NES port that make it stand out, such as new enemies and being able to use grenades in boss battles.

17 Ta🐠🥃nk Goodness

via: YouTube (arronmunroe)

As many gamers know, Japan sometimes gets some really great games that for one reason or another never see the light of day in the rest of the world. Battle City is one of those games. Released for the Family Computer in 1985, Battle City had players take control of a tank on a mission to protect their home base from a legion of enemy tanks. The game eꦗven allowe🗹d a second player to come in and help defend the base.

That's pretty cool and all, but even two tanks seems pretty few. What if we had four tanks at the same time? That'ﷺs what one modder had in mind when they released . Now those enemy tanks won't get anywhere near your base.

16 ꧑ Let's Get Dangerous 𓄧

via: Indie Retro News

Back in the early days of gaming, Disney had a slew of terrific and popular games, with many of them being developed by the legendary Capcom. None was more greatly remembered, though, than DuckTales, an amazing platformer based on an amazing cartoon series. It was so great, in fact, that Capcom made a sequel that was unfortuna🎉tely released well after the NES's time had passed.

As great as DuckTales 2 is, it would be a lot more fun to go hopping along with a friend. Of course, there's only one duck who can keep up with Scrooge M🌸cDuck. He is the terror that flaps in the night, he is the scourge who ! It's Using sprites from his own NES game, Darkwing plays pretty much exactly like Scrooge, but its awesome just to see two of Disney's greatest ducks sid💞e by side.

15 Catching Some🎃 Stars 𝕴

via: YouTube (PrestonLuigi 12)

Super Mario 64 is undoubtedly a Ninte♕ndo 64 classic. As one of the two launch titles for the system, it was Nintendo's first game to make use of a full 3D environment. But as engrossing as that game is, after you've collected all 120 Power Stars and defeated Bowser, what else are you left to do? Do the whole thing all over again?

Enter , a pseudo-sequel ROM hack created by Skelux. All the levels are redone, but they still manage to capture that same magic that made the original so special. The hack also contains ten more Stars than the original and features all new enemies and even music from other Nintendo titles, including Super Mario Galaxy, Super Mario RPG, and Bomberman 64. There's even a newer version that allows a second player to join as Luigi. A🤪 must-play for🔴 any Mario fan.

14 Pa꧒per Pals

via: YouTube (Gaming Zone)

Paper Mario was released toward the end of the Nintendo 64's lifespan, and even thoug🤡h it wasn't as popular as later entries in the series, it was still the best RPG on the system (not that that's saying much, ). It had an interesting plot involving the rescue of Star Spirits, as well as a number of interesting and unique partners you could control. But like all games, it would be better if you could play with a friend.

Skelux is back to the rescue, as he has developed that let's you play Paper Mario w🌟ith a friend online. Now, whichever companion Mario is traveling with at the moment will be playable and able to explore the environment as freely as Mario can.

13 Eight-Player Mayhem ♑

via: YouTube (UnitedWiiPlay)

Remember Micro Machines, those little toy cars that were direct competitors with Hot Wheels? Did you know that they have a series of video games based on those toy cars racing around kitchen tables and desktops? No? You were too busy playing Mario Kart 64 and Diddy Kong Racing to notice?

Well, one those titles, Micro Machines V3, featured 8-player races. Doesn't sound too hard to pull for an online PC game. But then that title got a port to the N64 renamed Micro Machines 64 Turbo. As with most console ports of the time, you'd expect some downgrading and removal of special features, but not in this case. The N64 port actually kept 8-playe♔r races. But how did this work?

In 8-player mode, players would share the controllers, with one player using th൩e directional pad to𒆙 move and the other using the C-buttons. A pretty innovative mode no one else tried.

12 ✨ Mega Fighte🦄r II Turbo

via: YouTube (Gamebrewer)

Mega Man 2 is often seen as not only the best title in the franchise, but as one of the best games of all time, and its hard not to see why. It has some of the best controls and gameplay on the NES, with many features that would continue to be used for the rest of the series. P🃏lus there's that . Honestly, it almost seems impossible to improve on such p🌜erfection.

Of course, multiplayer would be nice, s✤o someone out there decided to make a ROM Hack that would let a second player control the boss robots. This hack skiဣps most of the levels and just takes you straight to the boss room, essentially turning the classic 2D platformer into a fighting game. A lot of fun for fans of the blue bomber.

11 ♑ Shared Inv🐽entory

via: Games That I Play

In a sea of landmark Zelda titles, A Link to the Past still holds a special place in many gamers' hearts. It returned the series to the top-down perspective of the original and included an engrossing story revolving an alternate world and the Master Sword. Having been ported to the Game Boy Advance, Virtual Console, and Super NES Classic, it seems that there's nothing new to un꧒cover in this gem.

Fortunately, that's what modders are for. Thanks to the recent development of randomizer speedruns, players and ๊Twitch streamers are given an extra challenge when trying to beat thಌe game by having enemies and items spawn in different areas throughout the game. Someone decided to make the game more interesting by including a special code that would allow two players to synch their games, meaning whenever one player picks up an item, it will automatically appear in the other's inventory.