(For the similarly named freeware roguelike ''Spelunky'', click [[{{VideoGame/Spelunky}} here]]).

Classic video game created by Tim Martin in the early 1980s. ''Spelunker'' is about, as you'd expect, a guy who explores a large cave and looks for treasure. He has dynamite to help him blow up large rocks, flares to ward off bats, and a limited air supply. Adding a bit of fantasy to the game is the frequent appearance of ghosts, which need to be warded off with an air blaster. A pretty simple game.

Except for one thing: its [[NintendoHard sadistic level of difficulty]].

The spelunker himself can die very easily from a wide variety of things, including some you wouldn't expect:

* His own dynamite, of which the blast radius isn't actually visible (the entire screen flashes white when it goes off)
* Any enemy
* Bat droppings
* Falling in a small pit that's less than one half the already small safe fall distance
* His own flare landing on top of him on the way down
* Most infamously of all, falling less than his own height! (on NES version. The height of the player character was increased, while the vertical distances traveled were decreased.)
** And what's worse, when you're on a rope or a ladder, if you push left or right, you can actually slide off and end up dying in midair before you had a chance to jump off! The computer originals, mercifully, allowed jumping off of ladders and ropes safely by holding jump and tapping the stick, a luxury not allowed on the NES version.

That one involving falling is particularly nasty, due to the game's play mechanics. The spelunker can only jump a short distance, can't change his direction in midair, and falls straight down instead of slightly forward when walking off an edge. Your jumps must be very precise, or you will die from the fall - in midair, no less.

The game was widely forgotten in America, where it was created, but became a CultClassic in Japan due to its hilariously unforgiving difficulty and ludicrous number of ways to die. The game ended up being returned to used video game stores in high numbers when players got frustrated with it, but later developed a following among fans of NintendoHard games. As a result, there have been several Japanese fangames, and even a remake for Playstation Network in the form of ''Spelunker HD'', which adds multiplayer play and cartoony animations mocking the deaths, but also adds a lot of lives and a save feature to soften the blow.

The game actually inspired a Japanese expression, "constitution of a spelunker", which means someone who gets hurt badly from minor injuries.
!This game contains examples of:

* AWinnerIsYou: Expected in the NES version. Incredibly aggravating in ''Spelunker HD'' when you've just gone through 100 levels of PlatformHell to get there.
* TheAnimeOfTheGame: Titled ''Spelunker is a Teacher'', it's basically about the hijinks of the titular character as a teacher in a Japanese school. Some tropes associated with the anime:
** GratuitousEnglish: The opening theme, possibly a shout-out for Spelunker's American origin.
** [[HeyItsThatVoice Hey, It's That Voice]]: The titular character sounds like an even more unenthusiastic [[Creator/TomokazuSugita Kyon]], and the voice in the fifth PV sounds awfully like a certain [[Creator/NorioWakamoto Britannian emperor]].
* BedsheetGhost: One of the enemies.
* CartoonBomb: These can be used.
* EverythingTryingToKillYou: Ghosts, burst of steam, own bombs, fall traps, you name it.
* EvilTwin - In ''Spelunker HD'''s single-player mode, perhaps to compensate for the lack of getting killed by other players' mistakes in multiplayer.
* FallingDamage: Taken UpToEleven in this game, and part of what makes it so difficult. He dies in mid-air, even if he could have grabbed a vine or something on the way down.
* HaveANiceDeath - ''Spelunker HD'' adds cartoony death animations and even [[LampshadeHanging lampshades]] it in the tutorial, where you're told "In the tutorial, you have unlimited lives. Now's a good chance to find out what kinds of things can kill you."
* NintendoHard - As demonstrated [[http://www.youtube.com/watch?v=YzInicSbsWk&feature=related here]].
* NostalgiaLevel - The early levels in ''Spelunker HD''.
* OneHitPointWonder
* PlatformHell
** To elaborate, the NES version has vanishing ground that drops you to your death, secret powerups that can get you killed, invisible keys on the second loop, and lets you kill yourself by jumping while walking down a slope. ''Spelunker HD'' takes all of these and makes them even worse.
* RespawnPoint - The last place you picked up an "important item." Since most "important items" are at the end of long corridors filled with death, this forces you to go through the corridor 'again' every time you die.
* {{Retraux}} - ''Spelunker HD'' includes a "classic graphics" mode, which mimics the look and sound of the NES version, even though it also contains a lot of new content.
* RuinsForRuinsSake - Several levels in ''Spelunker HD''.
* SecretLevel - There are two exits from Stage 99 ... one of which requires an additional key not found in the stage. At least, not found in ''Stage 99'' ...
* SpiritualSuccessor - ''{{Spelunky}}'', which has the same premise and hatred toward the player, but with RandomlyGeneratedLevels and more features in general.
* UndergroundLevel - The entire game.
* VideoGameRemake - ''Spelunker HD'', which expands the game's original 6 levels to 100 levels, including a separate set of 100 multiplayer-only levels, while also adding new types of environments.
* WithLyrics - The main theme has had lyrics written for it in Japan (they mainly talk about how weak the spelunker is and how much he dies). [[https://www.youtube.com/watch?v=Qd_xQCCuA20 The anime's opening theme]] is actually a remix of the game's main theme and the stage clear theme, sung from the viewpoint of the titular Spelunker, albeit entirely in hilariously disjointed and nonsensical Engrish.