Secret levels used to be something extremely special. Before the Internet, you had to either find them on your own or hear about them from the weird kid at school who spent recess picking his nose and staring at the sun. And once you did find out about them, all you wanted to do was brag about your new found knowledge. Let's salute the greatest secret levels in videogame history.
It's hard to bring out something weird and unexpected in a WWII game where Hitler's dead and you're fighting with lightning-zappers, invincibility devices, and time-travel but then again, giant ants? Disbelief only suspends so far! It ends up feeling like Red Alert with Zerg, except with a lot more people saying "At once!" and "Affirmative!" over and over. The ants add a huge new challenge to the gameplay, where you have to radically change your strategy just to survive. Even then, it's hard as hell. So if you ever travel back in time and kill Hitler, remember to bring a giant can of Raid, okay?
George Lucas had to know that the Dark Side of the Force was the cooler one. I mean, would you rather be a badass asthmatic burn victim in black armor who hangs out with a grandpa who shoots lightning, or a wimpy blonde kid whose mentor thinks being a powerless ghost is "more powerful than you could ever imagine"? Clearly the Dark Side is the way to go something Rogue Squadron figured it out in their bonus level, "Triumph of Empire." It's a familiar moment, the battle above the Death Star (classic version, not that half-built piece of crap that Lando blew up with his midget friend) except you're in Darth Vader's TIE Fighter, wasting rebels left and right. And when it comes down to that pivotal trench run well, let's just say that Luke won't be bullseyein' womp rats again anytime soon.
The spiritual sequel to Goldeneye 64, Perfect Dark, gets pretty weird pretty fast: James Bond is now a sexy future lady spy, your first escort mission is with a floating laptop (still prettier than Natalya), and your best buddy is a little gray alien named Elvis. In the "Maian SOS" level, you actually play as Elvis and, as expected, it's pretty weird (spoiler: you end up dead on a toilet). You're at Oddjob levels of shortness, low on health, but despite being an alien still pretty efficient with handguns. No anal probes though. Which is sort've a bummer, considering all the time you spent on the colonoscopy training missions.
The best unlockable levels tend to mix up the formula a little which is definitely the case in "Big Blue." Taking place on an F-Zero track mid-race, your only salvation from certain KO is hopping across floating racers and resisting the urge to dive for that heart container falling towards the left side of the screen. All bets were off when someone with 0% damage could be KO'd as easily as a 500% Jigglypuff. If the rest of Smash Bros. is a crazy dance party, then "Big Blue" is the punch. The Falcon Punch. (I'm so sorry.)