History Main / SecretLevel

* The Windows versions of ''VideoGame/ChoRenSha68k'' have a hidden "Show Time!!" stage that can be only accessed by entering the secret options menu and changing the stage flag to a specific value. It's a BossOnlyLevel with [[BossBonanza three bosses back-to-back]] that [[EndlessGame repeat endlessly]], [[BrutalBonusLevel all of which are extremely hard]]; the first one is a [[KingMook large mook turned boss]] with unique, ultra-hard patterns, the second one is a similarly-overtuned verseion of the Stage 5 boss, and the last one is a unique SpiderTank boss not found in the main game.

* The Windows versions of ''VideoGame/ChoRenSha68k'' have a hidden "Show Time!!" stage that can be only accessed by entering the secret options menu and changing the stage flag to a specific value. It's a BossOnlyLevel with [[BossGame three bosses back-to-back that repeat endlessly]], [[BrutalBonusLevel all of which are extremely hard]]; the first one is a [[KingMook large mook turned boss]] with unique, ultra-hard patterns, the second one is a similarly-overtuned verseion of the Stage 5 boss, and the last one is a unique SpiderTank boss not found in the main game.

** ''VideoGame/TheLegendOfZeldaLinksAwakening'': While not present in the original UsefulNotes/GameBoy version, the Color Dungeon was added to the game's subsequent versions (DX and Switch) and requires solving a puzzle involving certain tombstones in the graveyard (a book in the library of Koholint Island provides a hint to solve it). The dungeon takes full advantage of the later versions' color displays, and many puzzles are accordingly based on them. Same with its boss, whose defeat also grants Link the ability to choose between honing his defense or his attack power.

** ''VideoGame/SuperMario64'' has various secret levels hidden in the hub area, and one more within one of the regular worlds (namely the one in Hazy Maze Cave, where you find the switch that enables the use of the Metal Cap). The UsefulNotes/NintendoDS remake adds even more.

* ''VideoGame/ChipsChallenge'': The game traditionally ends after completion of level 144 (''Fireflies''). However, by entering a password that is sneakily shown in the 34th level, it's possible to access level 146 (''Cake Walk'') and keep playing until completing level 149 (''Special'') which is the true last level.[[note]]Level 145's password isn't hinted or shown anywhere in the game, as in the UsefulNotes/AtariLynx version it only shows a Mandelbrot fractal application, while in the PC version it's a playable credits scene.[[/note]] All the {{Fan Sequel}}s (the ''Chip's Challenge Level Packs'') also have each levels 145 to 149 as secret, but the official sequel ''Chip's Challenge 2'' doesn't due to it eschewing the password system (it has 200 levels but none of them are secret).

* The UsefulNotes/SharpX68000 port of ''VideoGame/FantasyZone'' has a secret eighth stage, "Dragon Land," based on ''VideoGame/SpaceHarrier''.

** Episode 4 has one where you [[JustForPun collect 12 Inch Worms to make a giant foot]] which then launches you to a secret temple, the Pyramid of the Forbidden. It's a BrutalBonusLevel that features difficult-to-evade traps and hazards, as well as a high concentration of enemies.

** Each episode in ''Ultimate Doom'' has a secret map that is accessible via a secret exit in one of the Episode's maps:

*** In the Ultimate Doom portion of these ports, there's a new secret map called '''The Marshes''', which is accessible via a secret exit in '''Twlight Descends''', which itself is a new map exclusive to these ports. This map is a large arena resembling, as the name implies, a marsh-like area, containing a Cyberdemon and a handful of other mooks.
*** In the Doom 2 portion of these ports, the two secret Wolfenstein maps were replaced by two new secret maps:

** Episode 5 has a secret level accessible by clearing the penultimate mandatory level via an alternate route you can enter through a well-hidden entrance near the regular exit. It stands out for having an unusually tall design, to the póint of invoking IFellForHours when Billy falls all the way to the bottom; it's also unique for having two ways to be completed (with one of them providing a mild change in the game's ending).

* ''VideoGame/TheLegendOfZeldaSpiritTracks'': Some of the playable locations can only be unlocked by restoring rails with Force Gems that are rewarded by completing very obscure and/or difficult sidequests. Examples include the Snowdrift and Slippery Stations in the Snow Realm, and the Lost at Sea Station in the Ocean Realm.

* ''VideoGame/CommanderKeen'':
** Episode I has a secret level which can only be accessed by going down a tricky side passage in another level.
** Episode IV has one where you [[JustForPun collect 12 Inch Worms to make a giant foot]] which then launches you to a secret temple.
** Episode V has a secret level accessible by clearing the penultimate mandatory level via an alternate route you can enter through a well-hidden entrance near the regular exit.
** Episodes III and VI have each one secret level accessed from the overworld map. You have to catch a friendly monster (in the former) or a hovering vehicle (in the latter) so Billy is taken slowly to a distant section of the map that is impossible to see from anywhere else.

** ''Defender of the Future'' has Passage from Genesis and Pathways from Nowhere, bonus sidescrolling areas in Up and Down that harken back to the Genesis games.

** Each Episode in ''Ultimate Doom'' has a secret map that are accessible via a secret exit in one of the Episode's maps:

*** Episode 2 has '''Fortess of Mystery''', which is accessible via a secret exit in '''Command Center''', though its accessibility varies in early console ports; in the Super Nintendo port the secret exit to it was moved to '''Refinery''', in the Playstation and Saturn ports the secret exit to it was moved to '''Spawning Vats''', and it wasn't a secret map in the Jaguar, 32X, and GBA ports, instead being the final map of those ports. As for the map itself, it's notorious for its overt simplicity, consisting of just two plain rooms, one with four Barons, and the other with ten Cacodemons, with its purpose being to show off [[SetAMookToKillAMook monster infighting]].
*** Episode 3 has '''Warrens''', which is accessible via a secret exit in '''Mount Erebus''', though the map was removed in the Jaguar, 32X, GBA, Playstation, and Saturn ports (but interestingly it was retained in the SNES port). This map has the gimmick that it initially appears the player was sent back to the Episode's first map, '''Hell Keep''', being exactly the same as that map up until the secret near the end, which no longer has a Rocket Launcher, the first signal that something isn't right. Then when the player steps onto the "exit" teleporter, [[VictoryFakeout the walls come down to reveal a large arena with a Cyberdemon]], and then the player must backtrack through the map, with more rooms opened up containing more dangerous enemy encounters than the original map had.
*** Episode 4 has '''Fear''', which is accessible via a secret exit in '''Perfect Hatred''', though the map was removed in the Playstation and Saturn ports, and of course doesn't exist in the other console ports that don't have Episode 4 (the SNES, 32X, Jaguar, and GBA ports). It's a banal conventional map that is noticeably much easier than the two Episode 4 maps precededing it, with its only noteworthy feature being its symmetrical design.

** ''VideoGame/DoomII'' has two secret levels set in levels taken from ''VideoGame/Wolfenstein3D'', with one accessed from a secret exit found in the other. The second one requires you to kill four clones [[spoiler:of VideoGame/CommanderKeen hanging from a noose]] to access the exit.

* The secret levels in ''VideoGame/PerfectDark'' are retreads of previous levels from a different point of view, which reveal different parts of the story. The first one shows how an alien {{Mook}} [[spoiler:kidnapped the CEO of dataDyne (she was later killed aboard the ship) and imploded the building, effectively destroying the company]]. The other two missions let you play as the [[TheGreys grey]] aliens, one where Elvis alerts the Institute of being captured by Area51 and you play through the entire level with diminished health, and the other has you play as a soldier among a platoon who landed on the planet after Joanna dropped the shields. Both missions are ''[[BrutalBonusLevel insanely]]'' difficult.

* ''VideoGame/Wolfenstein3D'' has one secret level in each episode (two in ''Spear of Destiny''). Of note is the one from Episode 3: It's a gigantic maze where you collect bonus orbs for high score where you're beset upon by four ghosts. Four giant colourful ghosts. With googly eyes. Yes. It's a level of ''VideoGame/PacMan''.

* ''VideoGame/DonkeyKongCountry2DiddysKongQuest'' and ''[[VideoGame/DonkeyKongCountry3DixieKongsDoubleTrouble DKC3]]'' have a "secret" world that allows access to a better ending, and certain items you collect are focused around gaining access to these levels.

* ''VideoGame/WaltDisneyWorldQuestMagicalRacingTour'' has the Splash Mountain track, unlocked by coming in first twice on the other nine tracks. The game does a good job of hiding it...but not only does the manual tell you how to unlock it, the list of tracks in the back includes Splash Mountain with the notation "Secret Bonus Track". Nobody told the manual writer what "secret" meant, apparently.

* In ''LightNovel/SwordArtOnline'', there is a dungeon below the first floor of Aincrad that houses incredibly powerful monsters that don't typically appear until the 90th floor. The leader of the Aincrad Liberation Front, Thinker, gets trapped in this dungeon because of a power-play by Kibaou, who used the dungeon to grind levels in secret.

** The three standard secret levels in the main campaign provide tangible rewards found nowhere else. Each gives one of three Demon Keys to power up your Unmaker weapon, provided you solve a puzzle in each level. You can also find significant perks, such as an Unmaker as early as the first act of the game. [[spoiler:Each Demon Key also reduces the difficulty of the final level ''significantly'' by allowing you to close one demon portal per key.]]
** A super secret level called Hectic, accessible by reaching the secret exit of the first normal level, doubles as a BrutalBonusLevel for featuring traps that are extremely difficult to overcome. But if the player prevails, they will unlock a set of features like accessing hidden levels that are unavailable otherwise.

* ''VideoGame/{{Doom}}'':

** The Playstation 1 version of the original game has two secret levels (one being the iconic "Club Doom") that remain exclusive to this version of the game. One is only accessible from within another secret level.

* ''VideoGame/SeriousSamTheFirstEncounter'' has two secret levels: "Moon Mountains" and "Sacred Yards", reached by finding alternate exits in "Valley of the Kings" and "Luxor" respectively. The former is a detour through the source of the Nile and a break from the sandy deserts and canyons of Egypt. The latter is a GimmickLevel where enemies are hidden in every single destructible object, placed right before the final level of the game.

* ''VideoGame/Wizardry'' has these in Wizardry 8's three hidden "Retro Dungeons", which take the form of old, grid-based dungeons made as they were in the 1980s using early 2000s graphics. None of them have anything to do with the main plot and some contain monsters not found in the "real" game outside of them, such as golems made from coal, or box-like "kube" monsters which appear to have been made using geography assets from the game's construction kit.

** ''VideoGame/WarioLandSuperMarioLand3'': Starting from this game, almost every game in the ''VideoGame/WarioLand'' series has many secret levels, including whole secret worlds.

** In both ''VideoGame/SuperMarioGalaxy'' and ''VideoGame/SuperMarioGalaxy2'', Hungry Lumas take Mario and Luigi to secret galaxies after they're fed with enough Star Bits.