This was, quite possibly, the coolest nintendo game ever. I don't think many people have heard of it, but it rocked my world.

It was really pretty simple; the levels were all the same except for the placement and arrangement of the blocks and floors, although that made all the difference in the universe. It's hard to describe verbally, although if you could just see a screenshot you would understand the whole thing immediately-- you were climbing a mountain, basically, except not the standard large upward outcropping of rock caused by plate tectonics that we normally associate with the word "mountain"-- this was some kind of a multilevel industrial meat locker. You had a series of floors stacked on top of each other, with each floor floored and ceilinged by a layer of floating ice blocks. On the edge of each floor you had this kind of weird metal industrial-looking border thing that looked slightly different for each floor. The standard nintendo rule of if you run off the side of the screen, you appear on the other side applied.

And basically what you'd do is climb from floor to floor through holes in the ice. And if there weren't any holes you'd make them. Your little character you controlled, who was buried in a huge parka, had this kind of freaky hammer/axe thing {s}he (for some reason that escapes me, we at the time considered the first player's character to be a boy, but the second player's character to be a girl) would wield as a weapon as well as hold above him/her whenever {s}he jumped. And so when you jumped you would knock out a section of the ceiling above you. And eventually you'd be able to jump through it.

Things more complicated; you had to deal with these irritating birds flying around, occasional falling icicles, and most importantly of all, seals which walked around looking for holes in the ice and then trying to fix them. They were kind of like mindless automatons performing maintenance for a huge self-serving self-maintaining machine, except that they were seals. And some levels would have walls in them, some levels would have conveyor belt floors, and sometimes instead of ice blocks you just had moving, floating platforms. In any case falling off the bottom of the screen meant death, and each level ended with a funky obstacle course in which you tried to climb weird irregular platforms and eventually jump into the arms of a giant pterodactyl (???)

The two-player mode was the best, though-- you'd have two players going at once and occasionally getting in each other's way.

An update:

Apparently at some point Nintendo changed things such that in later Ice Climber cartridges, the floor repair automatons were not seals, but wierd little balls of spiky white fur with beaks. This is, one would assume, done because the seals tended to provoke responses like anamnesis' writeup below, whereas people have a hard time relating to hairballs, unless they read User Friendly.

Ice Climber has enjoyed a little renaissance lately, as part of Nintendo's intensive retro-exploitation strategy that they have been employing with the Gamecube. The Ice Climbers were playable characters in Super Smash Brothers and Super Smash Brothers Melee; Melee featured the Ice Climbers' "infinite mountain" as a play arena, and an entire Ice Climber level replicated in the Target Smash training level for the Ice Climbers characters. Sadly, the Ice Climbers were, in Smash Brothers Melee at least, hopelessly and unfairly weak; while very fun to play with, and posessing some decent smash attacks, the Ice Climbers are so incredibly outmatched in Melee as to be totally unusable unless you are purposefully trying to handicap yourself. Super Smash Brothers Melee informs us, incidentally, that the blue and pink Ice Climbers were indeed male and female, and their names are Popo and Nana.

Ice Climber is also one of the games playable on the GBA with e-reader cards; the pterodactyl catch at the end of all Ice Climber levels provides one of the Wario Ware Inc. minigames; and Ice Climber is one of the NES games which is programmed into Animal Crossing, but impossible to obtain in any way within the game without using an Action Replay. All recent Ice Climber materials have used the little spiky furballs; Smash Brothers Melee features of a trophy of the furballs but makes no mention of Nana and Popo's dirty little secret, the seals.