We're in the business end of our games of the generation series, and having run down through our top ten we're now into the top three, as voted for by Eurogamer contributors. First up it's Spelunky, Derek Yu's spectacular platformer that's enjoyed several console revivals throughout the last few years.

Linda Hamilton was right: The machines will rise. Spelunky, much like Skynet, was created by a man - in this case Derek Yu - but each of its individual playthroughs is constructed by a soulless algorithm that somehow designs stages that are at once fair, intriguing, well-rounded and challenging in a way that only the best level designers could hope for.

It's not that Spelunky was the first game to introduce procedurally generated levels, a practice that's been happening for over a decade in various dungeon crawlers and roguelikes, but rather Spelunky was the rare gem that reconstructed its architecture each go-round in a way that didn't feel arbitrary or like a cheap ploy to lengthen the experience. It understood the plight of man and knew exactly what challenges would feel worthwhile, and which would simply feel unfair - and in the several hundred games of Spelunky I've played (across three platforms, no less), I could count the number of supposedly "cheap" deaths I've had on one hand.

Prior to Spelunky, whenever I heard the words "procedurally generated" I equated it with "dull and devoid of personality". I preferred the meticulously authored, painstakingly detailed hanging gardens and grandiose caverns of Castlevania to the vapid shifting walls of Pikmin 2, Dark Cloud 2, Diablo and Boktai. The environments in these games' dungeons always felt drab with poorly choreographed haphazard challenges. I'm sure a lot of work went into programming these procedurally-generated levels, but the end result always struck me as the game developer equivalent of a deadbeat dad sticking his child in front of a TV and saying, "this should keep you entertained," before ducking out to the pub.

Spelunky doesn't have a story beyond 'loot treasure from a cave,' but that's all the setup it needs. It even ties in with the somewhat divisive scoring system that's predicated entirely on money earned.

With this quantity-over-quality mindset, I went into Spelunky enormously underwhelmed by the whole affair. The chunky grid-like dirt walls, wispy whip, simple enemy attack patterns, and the constant fear of running out of ropes midway through a run and having to start all over left me thinking of Spelunky as little more than a moderately amusing distraction for those who don't care about game design. As for me, I quickly bailed and instead spent my time revisiting Dark Souls trying to deduce the mindbogglingly intricate mechanics From Software had whipped up.

Sometimes I'm wrong about things.

It's easy to be wrong when a game is this far ahead of its time. Without the proper lens to evaluate this kind of work, it's tempting to compare it to what you know (in my case Metroid and Castlevania), and critique it for what it's not. Embarrassingly, I recall the first time I encountered Ico a few years after it came out and I found myself underwhelmed by its dull combat and simplistic puzzles. What was I expecting? Grim Fandango? Zelda? Prince of Persia: The Sands of Time? Evaluated under the same rubric of these others games, Ico did have dull combat and simplistic puzzles, but that wasn't the point. Instead, it formed a strong narrative experience that paved the way for future mechanics-light experiences like Gravity Bone, Dear Esther and Gone Home.

Spelunky followed a similar trajectory for me - albeit on the complete opposite end of the spectrum to Fumito Ueda's masterpiece. Spelunky is entirely about its mechanics and how they intertwine with one another to create something as endlessly engaging as any game I've played. Deconstructed into its constituent parts, nothing in Spelunky is that remarkable. The enemy behaviours, cavalcade of weapons, and bevy of items aren't especially unique or innovative. There's no Portal gun, for example.

Initially the idea of stealing from shopkeepers is unthinkable with their caffeine-addled, shotgun wielding ways, but look up videos and it becomes clear that murdering and looting them is a legit pro strategy.

The genius of Spelunky is how harmoniously all its pieces tie together to create one of the most hilariously hazardous emergent obstacle courses ever created. Here's an example. Throughout the ice caves, the game's wintry third area, there are flying saucers that blow up a chunk of the level when they crash (meanwhile, their adorable one-eyed green alien pilot parachutes to safety). I was feeling pretty cocky sporting a jetpack and brandishing a shotgun, an unlimited ammo weapon that shoots a spread of bullets across the entire stage. Well on my way to a run that seemed likely to set a new record, I nonchalantly shot down a UFO from across the screen. The force of the gun caused the craft to plummet a few paces from where it was hit, and upon crashing into the earth its explosion sent a landmine flying square into my face. Bam! Game over!

In a matter of seconds I went from the most armed motherf***** in all of Spelunkyville to a petty number much further down the leaderboards than I was destined for. This death may have seemed unfair to a new player, but I knew how the alien aircraft would upset the scenery. I knew how the shotgun blast would affect it. And I knew what a landmine would do to me. To quote Tom Bramwell in at least one of his Spelunky Daily Challenge runs "Why didn't I look?!"

And that's the kicker: Spelunky is a funny game. A really funny game. Upon every death is a sudden jolt of anger, frustration, and ultimately self-deprecating humour. Not only is every failure in Spelunky most definitely your fault, it's almost always emanates from overcoming an obstacle that isn't very difficult in the first place. "Why didn't I use another bomb?" "Why didn't I use a rope?" "Why did I latch onto that ledge" are common thoughts upon meeting one's maker in Spelunky. A reaction that's typically succeeded with hitting the "try again" prompt.

But perhaps what makes Spelunky most special is that there's a reason to its madness. The walls aren't shifting simply to slightly alter the geometry, but to provide a radically different experience. Yes, some playthroughs will be more difficult than others with stingier resources and viciously dark levels, but a careful player can always surmise the situation and come through unscathed. Do you use your bombs to go for the hit-point-giving pug or do you save those to try to access the clandestine Black Market? Do you slay that shopkeeper with a freeze ray to steal his shotgun even if he doesn't have anything else you want, or wait until you have a better reason so as not to incur the wrath of his brethren? Do you expend some ropes to explore a part of the level you haven't been to yet, or retreat through the clear exit? Spelunky's ever-changing architecture is crucial to its exemplary risk vs reward system and the further you get into the game, the more the procedurally-generated system feels not only justified, but absolutely essential.

Spelunky's multiplayer may not be revolutionary, but it's still a heck of a good time, particularly in the competitive mode.

Of course procedurally generated risk vs reward designs date back to tabletop RPGs and Rogue, but what makes Spelunky special is that its original free PC version was one of the first games to transplant this archaic genre into an easily digestible reflex-based action game. I've been playing games long enough to realise that there are some mechanics that either gel with a person or they don't. Gene Siskel once said that the two things in life that can never be argued are sense of humour and sexual attraction, but I'd add game mechanics to that list. I've found that turn-based, menu-based RPGs are an acquired taste that I, and a heck of a lot of other people, haven't acquired. The 2D platformer is likewise not for everyone, but I don't think it's a stretch to say it's a broader, more accessible genre. You run. You jump. You attack. Everything else is an easy to grasp additive that anyone can come to grips with.

This, in turn, spawned a whole new wave of action roguelikes. There's the top-down retro horror dark comedy stylings of The Binding of Isaac, which takes Spelunky's general template and splices it with Zelda and Dante's Inferno; Tokyo Jungle follows a similar format only with an added third-dimension, more wildlife, and some shagging; Paranautical Activity merges the mold with Doom-like FPS action; Teleglitch approaches the genre with a lo-fi sci-fi horror angle; and the upcoming Daylight is a relatively high-budget attempt at bringing the Spelunkylike to an Unreal Engine 4-based first-person affair. Need I mention Rogue Legacy, Don't Starve, or FTL? The point is the action roguelike is here to stay.

Furthermore, Spelunky is a stellar example of how a tiny indie game made by one man can change the industry (though the HD remake was aided by programmer Andy Hull and composer Eirik Suhrke). Of course Spelunky may not be the best example of that with Markus "Notch" Persson raising the bar on that mantle with the tens of millions of dollars he made from Minecraft, but Spelunky still remains one of the forbears in the ever-emerging indie scene - something that pretty much began and ended with Chinese whispers about Cave Story before this generation began in late 2005.

Ultimately, Spelunky, like Ico before it, was something of a pioneer. Without a strong gimmick to its name it would be easy for newcomers to write Spelunky off as a heartless void of a platformer where the player is at the mercy of a clockwork algorithm, but that would be a mistake. Spelunky is the gift that keeps on giving. Even when all of its secrets have been discovered, enemies vanquished, and items found, it still beckons me back for another go, as I know I've only gotten stronger, faster, and all around better at conquering its unpredictable challenges. Every shot is an adventure: a chance to prove I can overcome the odds, take bigger risks, and maybe, just maybe, come out the other end with a new high score. But more likely I'll get knocked onto some spikes. No matter. I know the very next day I'll be back.