Spelunker was a big hit on its original platform, the Atari 8-bit, for being the first game of its kind to have such a large scale and multi-directional scrolling. Irem licensed the game from Broderbund and made an enhanced arcade version and a version for the NES, which became an infamous kusoge notable for killing the player for falling short distances and requiring precise inputs for jumping off of ropes.

If you can look past that, though, it's quite fun. The arcade version is much easier and forgiving, and it seems the NES version was due to be more like its arcade counterpart.

Debug Mode

A simple debug mode can be reactivated with the Game Genie code AXVEPTAA. During the game, press Select to enable invulnerability and free movement through the wall.

Unused Graphics

To do: Add images to compare the unused NES graphics to their used arcade ones.

Falling

In the arcade version, the player could fall long distances without dying, though doing so drains the energy meter much quicker, and an animation similar to this one plays. In the NES version, the graphic for falling is just the standing graphic, and you die after falling the same distance as the player's height.

Bump

In the arcade version, whenever you bump into a wall you smack into it and bounce back, which uses the left frame. If there is no floor to land on, you begin falling, otherwise you land on your back. In the NES version, bumping into a wall makes you fall straight down with no animation.

Lean

In the arcade version, you can lean left or right off ropes before jumping, playing an animation similar to this one. In the NES version, if you press Left or Right on a rope without simultaneously jumping, you let go of the rope and start to fall. The lower half of this graphic is not present in the ROM.

Ledge-Up

In the arcade version, some ropes and ladders lead to platforms which you can climb onto, and an animation similar to this one plays. In the NES version, all ladders and ropes lead to solid ceilings, so this animation is never used.

Sleeping Bat

In the arcade version, there are bats which hang on ceilings until the player comes by, after which they swoop down and attack. In the NES version, all bats are awake at all times and instead stay in one spot and drop guano.

Dead Bat

Bats cannot be killed in the NES version, so this goes unused. Bats can be killed in the arcade version, but they vanish instead of leaving bodies.

Potion

In the arcade version, potions refill your energy instead of the generators used in the NES version.

Sparkles

Lots of things sparkled in the arcade version, but nothing does in the NES one.

Fireballs and Explosions

In the arcade version, your flashlight actually shoots explosive fireballs(!) and your bombs make visible explosions; in the NES version, your flashlight only kills ghosts and bombs just make the screen flash.

Developer Credit

The US version has a small credit at 0x701B:

REMAKE TAMTEX