"My first line was 'Snake Vs Monkey'", says Metal Gear Solid 3's David Hayter: "I could only ask, 'Why am I saying this?'"

Gaming's always embraced crossovers, even before the launch of PS1, with apparently disparate IPs getting together in titles like Battletoads & Double Dragon. Later in the '90s crossovers started to really take off thanks to fighting games like Capcom's bouts with Marvel and SNK, and even manga character Gon's appearance in Tekken 3.

Suddenly the floodgates were open, and everyone had their own hopes for crossover games. Dream crossovers like Street Fighter Vs Mortal Kombat, Crash and Spyro, or Jak and Daxter teaming up with Ratchet and Clank, were becoming highly requested. Luckily for PS2 owners, one of the most obvious crossovers ever came to be when Metal Gear Solid crossed over with… Ape Escape.

Son-keys of Liberty

Okay, so, maybe Ape Escape and Metal Gear aren't exactly a destined duo. But for whatever reason, the powers that be decided that for the third entry in each series, Snake and the titular apes would cross paths. Reasons that even Snake's actor himself – David Hayter – was unaware of. "While we were recording MGS3, they just came in and handed me a script," he tells us, "and my first line was 'Snake Vs Monkey' and I could only ask, 'Why am I saying this?'"

The reason a state of emergency is declared: apes have escaped and fled to a Russian jungle, and the only people able to stop them – Spike and Jimmy – are away on summer vacation. With nowhere left to turn, the professor goes to Roy Campbell, who knows just the man for the job: the legendary soldier Solid Snake. Snake – begrudgingly – is ripped away from his own holiday at 2am and enters the jungle in search of Specter's mind-controlled simians.

"They just told me that it was a side-game and that was all," recalls Hayter, adding, "Y'know in Metal Gear, they ask you to say a lot of weird stuff; you just sort of roll with it." Sadly, aside from a small intro scene to set the stage, Hayter's voice talents weren't utilised during the minigame.

Snake Vs Monkey sends you through seven stages (each with a title that's a pun on a film's, such as 'Ape Fear' and 'The Apes Of Wrath') in which you must search for and catch those cheeky monkeys. It's a fairly simple minigame, reusing the level design and mechanics of Metal Gear Solid 3 in a faithful recreation of Ape Escape. It even features a level set in the field where Naked Snake and the Boss have their final battle in one of MGS' most emotional moments, now filled with funny little monkeys. Hayter muses, "Y'know it's kind of the soul of Metal Gear; it goes from the sublime to the ridiculous."

While there are some fun touches, like a Shagohod-inspired ape mech in a couple of the stages, they are merely cosmetic; the game boils down to shooting targets with the EZ Gun and running into them. Still, for a small side-game in one of best games ever made, it's a fun distraction.

Snake Escape

Snake Vs Monkey could have easily been an enjoyable little side-game in MGS3 and that would've been the end of it. However, Japan Studio had other plans. When Ape Escape 3 was released less than a year later, the developer had its own take on the crossover with the Mesal Gear Solid: Snake Escape minigame. That's no typo. 'Mesal' is a portmanteau of the Japanese words for 'metal' and 'monkey' – 'metaru' and 'saru'. Once again Snake would meet the apes; however, this time David Hayter would not be brought in to voice the legendary Metal Gear hero. "I think it's the first I'm hearing about it," Hayter exclaims when we ask.

Instead, the role was given to another Metal Gear Solid alumnus, Vulcan Raven actor Peter Lurie, who tells us that "someone who knew me from some of my other work came to me and said 'We really want you to play this part.'" Lurie was given very little information in advance. "It wasn't until I actually walked in there that I realised it was playing Snake, which I was a little surprised at but thought, why not? Let's see what happens."

Ape Escape's Professor is doing his laundry, when he gets a call from his best pal from school, Colonel Roy Campbell. He informs Professor that he has lost contact with Snake, who was infiltrating a base to destroy the newest version of Mesal Gear, and needs help locating him. It turns out that a specially trained ape guerrilla force has commandeered the latest Mesal Gear and is demanding ten billion bananas within 72 hours or they will fire the mech's 'Lazy Cannon.' Campbell requests the help of the elite ape-catching force of Spike and Jimmy… who are once again away for the summer.

When all hope seems lost, Professor has the brilliant idea of uploading Snake's battle data into a monkey helmet, and thus Pipo Snake is born. In addition to the battle data, Pipo Snake also took on Snake's voice actor. Even though Lurie was pulling double duty, he quite enjoyed playing Snake's monkey variant, saying "they [non-verbal characters] can be a lot more freeing because it can be left up to your own interpretation."

While Snake Vs Monkey is a touch underwhelming, all things considered, Mesal Gear Solid is shockingly ambitious. Set aside all the apes and the game feels like a legitimate Metal Gear Solid adventure. The opening areas emulate iconic scenes from MGS1, such as the elevator and the initial approach into Shadow Moses from the beginning of the game, as well as a fist fight on top of a destroyed mech from the finale. The game doesn't stick to co-opting areas from past Metal Gear games, however, and that old Ape Escape flair is soon added with levels inspired by the likes of Edo Japan and the Wild West. The developers even use small touches like cutscene direction, the way the guards patrol, and posters adorned with bikini-clad monkeys. All of these go to show that this was a true love letter to the greatest stealth series of all time rather than some half-baked crossover mandated by a publisher.

Bananas of the Patriots

So, how do you get into the mindset of a battle-hardened ape? According to Lurie: "If I remember correctly – and this happens a lot with characters who don't speak 'the Queen's English' – you're given a 'We want a response and this is what emotion we want to convey.'" However, even when your dialogue is as simple as making 'oo-ki' noises, the direction is taken as seriously as any other. "There will be times where a director will tell you in a polite way 'That's really good but let's try it this way, remember, you're trying to convey this.'" Lurie says that's "someone's subtle way of trying to say 'Yeah, that's not it.'"

Of course, the Metal Gear series is known for jumping between utmost seriousness and utter ridiculousness at the drop of a hat. Working on those games, it seems, acclimatises you to the extreme ends of the job. David Hayter agrees with this, saying, "It's kind of cool to create a world like that, where the serious stuff, tragic stuff, and hilarious stuff all comes together." He adds, "I think it's kind of comforting for people when the game developer is confident enough to joke with you. That's the kind of stuff that fans come up and talk to me about all the time. I always feel like when a situation is dire people tend to joke, and, in a way, it sort of mirrors life."

A version of this article originally appeared in PLAY Magazine – which printed its final issue in 2024. More stealth needed? 7 years on, Agent 47’s attempt to contain a deadly virus in Patient Zero brings the classic Hitman stealth action to an unmatched fever pitch