''Deep Fear'' is a 1998 SurvivalHorror game for Sega Saturn, known for being the last Saturn game to reach Europe.

The player controls John Mayor from the ERS, a sort of civilian mercenary group specialised in rescues, stationed in the ''Big Table'', an underwater army base. As the game begins, the submarine ''Sea Fox'' delivers to the base a capsule which recently fell out from space. Suddenly, the submarine inexplicably crashes, opening all its nuclear missiles hatches. John manages to go in the wreck and deactivate the hatches, but ''something'' came from the ''Sea Fox'' to the ''Big Table''...

''Deep Fear'' is VideoGame/ResidentEvil '''[[RecycledInSpace IN THE OCEAN!]]''' The main feature that sets it apart from Resident Evil is that it has an OxygenMeter that decreases as you move. To complicate matters, certain areas have less air than others, so time is of the essence.

The music is composed by Kenji Kawai [[HeAlsoDid who also composed]] ''Anime/GhostInTheShell''.

WebVideo/{{Retsupurae}} did [[AlternateDVDCommentary their usual schtick]] on a longplay of the game. View it [[https://www.youtube.com/playlist?list=PLo4M1tlpv9rs56eGswbent2N36ntnTnsO here]].
!!The Tropes associated with this game are:
* AnyoneCanDie [[spoiler: ...and almost everyone does. The only survivors are John, Andrew (Sharon's dolphin), and Rambo (Anna's bulldog).]]
* AprilFoolsPlot: The entire game takes place during April 1st, 199X. The game starts off with Mookie and Sharon playing a joke on John. Not soon after, when John informs Clancy of the monsters, Clancy's initially inclined to believe it's just a practical joke.
* ArtisticLicenseMilitary: For some reason, the man in charge of the Navy [=SEALs=] is called Colonel, despite the fact that there are no colonels in the Navy. (The Navy equivalent of a colonel is a captain.) Also, for some reason an Army Colonel is in charge of an underwater base.
** Near the beginning, John Mayor has to get two keys to deactivate the launch of nuclear missiles from the submarine "Sea Fox". This much mirrors the real-life security system PAL's two-man rule. What ''doesn't'' match it is how both keyholes are within arm's reach from one spot, allowing John to turn both keys at once...
* BeneficialDisease: Downplayed; [[spoiler: Having a Cold protects John from TheVirus.]]
* BishonenLine: The first form of the final boss is something resembling a BlobMonster. However, its final form is [[spoiler:Gena transformed into a glowing and rather [[CuteMonsterGirl attractive]] fairy-like creature.]] It definitely stands out amongst all the BodyHorror found elsewhere in the game.
* [[spoiler:BittersweetEnding: John survives and puts a stop to the virus before it can spread to the rest of the planet... but fails to save any of the other characters.]]
* BodyHorror
* BlatantItemPlacement: An admitted flaw is that there are so many items placed everywhere that there's hardly any challenge to the gameplay.
* {{Camp}}[=/=]JustAStupidAccent: Dubois Amalric. His voice is so flamboyantly gay-sounding, it's hard for it to be anything else.
* TheDogWasTheMastermind: [[spoiler: It turns out the source of the infection was Gena's chimp Anthony, who was really a NASA chimp that had been floating in space for decades, causing the bacteria in his body to mutate due to cosmic radiation exposure. Also, Clancy and Gena were behind the secret viral research that ended up causing the outbreak.]]
* DoNotRunWithAGun: Averted. John can walk ''and'' run even with his gun ready to shoot.
* {{Expy}}: Anna is one of [[Film/{{Aliens}} Vasquez]], up to [[spoiler:succumbing to [[VasquezAlwaysDies the trope named after said character]].]]
* HeroicSacrifice: [[spoiler: Dubois stays behind to blow up a building as he slowly transforms into a monster, allowing John to escape. [[SenselessSacrifice It's a shame he becomes a monster and survives anyway to attack John.]] ]]
** [[spoiler: Danny gets attacked by a [[AndThenJohnWasAZombie mutated Anna]] and sends John and Gena off so he can activate the elevator for the two of them to escape.]]
* HopeSpot: Nearing the start of Disc 2 a fellow survivor catches a cold. It had been established earlier that [[spoiler:a cold is what's stopping the infection from affecting John; thus, you'd think the same could be said for her]]. Unfortunately, [[spoiler:she still ends up becoming a monster shortly afterwards.]]
** Well, [[spoiler: she '''thought''' she had a cold...]]
* HollywoodScience: The end cut-scene is the most aggravating case, for we see [[spoiler:John emerge from the escape pod into open air after spending the whole game in a deep-sea compound. In real life, he should have been taken to a decompression chamber, or the sudden change in air pressure would have killed him]].
** Even more aggravating is the Flooded Rooms, you would think opening a door to a flooded area would release water into the room connected to it. This includes one particularly mind-boggling case toward the end: you have to climb up a ladder, from a room below that's perfectly dry, into a room above that's completely flooded. Not even ''gravity'' can circumvent whatever magic is preventing adjacent rooms from flooding.
* HorrorDoesntSettleForSimpleTuesday: The game is set on AprilFoolsDay. This actually leads to a few scenes where John tells people of horrific monster attacks, [[NotNowKiddo but they don't believe him because they think it's part of an April Fools' joke]].
* [[spoiler: KillEmAll: John, Andrew the dolphin, and Rambo the bulldog are the only survivors of the game's events.]]
* LawfulStupid: A lot of the people within the game are nice, kind people, all things considered. Even Clansy, who [[spoiler: killed hundreds of civies]] isn't THAT bad a person. Yet people throughout the entire game put their ethics and goodness ahead of common sense: practically none of the people in the apartment complex are willing to leave, and most egregious of all, Danny, who KNOWS full well the risks of staying in the area he occupies, refuses to evacuate because the man informing John it's time to go is Clancy. Sure, he has good reason to loathe Clansy [[spoiler: being the sonar man who realized what Clansy was doing when he ended up killing civies]] but even still, the explosions and power outage that have rocked the Big Table are CLEARLY getting worse. That, along with a declining amount of air, should have ALL the personnel and civilians evacuate immediately.
* LoadBearingBoss: ''Three'' of them.
* PainfulTransformation: Victims of the virus go through a pretty painful metamorphosis with random abscesses and growths erupting from various parts of the body, which the game excitedly shows off in the [=CGI=] cutscenes from multiple camera angles. At one point, a victim's [[{{Squick}} fingernails start popping off]] for no real plausible reason other than to disgust the audience.
* [[spoiler: OneWingedAngel: Gena's final mutation is that of a winged, green-skinned woman. Oh, and her voice echoes and she glows so hard she can blind you.]]
* OxygenMeter: Each room holds a limited oxygen level represented by a time counter, which goes down faster if you use your weapons. You also have the rebreather, a tiny oxygen bottle you use in the rooms without air, which has a meter, making it a more straight example. Luckily, the save points allow you to reload the rebreather and all the rooms of the area you're currently in.
* RescueRomance: Between John and Gena. [[spoiler: Her mutating into a monster at the end of the game puts a bit of a halt to things, though.]]
* SanitySlippage: Commander Clancy undergoes this late in the game. [[spoiler:He goes from wanting to save all the other survivors on base to leaving everyone else to die by taking the SEALs' DSRV while ranting about killing the remaining survivors from the cruise ship he sank.]]
* SelectiveGravity: In the flooded rooms, John and the monsters can walk and run like normal, even though you can see a floating corpse in the very first flooded room John comes across.
* ShoutOut: It can't be a coincidence that a game made by Sega takes place in the Sea Fox. (The name of Tails' submarine in TailsAdventures.)
* StalkerWithACrush: Sharon to John.
* SoundtrackDissonance: The music may be the only genuinely good thing about the game, but the songs rarely seem to match the tone of the scene they're in.
* TrickBomb: John carries around a slew of "air grenades" with him; when they explode, they fill the room with breathable oxygen. At one point, he also gets a fire extinguisher "capsule" that also works like a grenade.
* UnderwaterBase: The setting for the game, "The Big Table", is a military base set on the ocean floor. Proved to be overly expensive to build (who'd have thought?), so civilian corporations have a presence as well.
* [[spoiler:VasquezAlwaysDies: Anna looks like she can hold her own, right? Heck, she even catches a cold, which was established to prevent John from turning himself, so she's totally gonna be fine. Oh, wait, no, she's turned into a monster, and you have to kill her. Figures. (For what it's worth, though, even the ''less'' macho women end up dying too.)]]
* WalkDontSwim: John Mayor apparently has zero buoyancy, as he still walks in flooded rooms.
* [[spoiler:WeaksauceWeakness: As it turns out, ''the common cold'' is an effective vaccine for the mutant virus. It also has some weakness to oxygen, but that's actually a weakness of many microscopic organisms, so it's not as bad.]]