Remember a few weeks ago when we ran down the easiest Achievements you could possibly earn over Xbox Live?  (And that's including the gift-wrapped 1,000 points you'd get from the latest Avatar: The Last Airbender game.  You're welcome.) 

That's child's play compared to the Achievements we've got lined up for you today.

We've done some painstaking research and decided to finish off November with ten ludicrously impossible Achievements to earn.  Not all of them are that bountiful when it comes to point count, with some even being less than 50. 

If you can unlock these, you can show the world that you, in fact, have arrived as a true gaming pro.

Tackle with great care, and good luck.  YOU WILL NEED IT.

Mega Man 10- "Mr. Perfect"

For 30 GamerScore points, you can add the "Mr. Perfect" Achievement to your collection by beating Mega Man 10.  But this is hardly something for every retro fan to take on, as the game will only reward you if you manage to get through the game without getting hit.  At all.  We're talking through boss battles, dodging stray bullets, and avoiding losing a life.  Even with the easy settings turned on, this is the sort of thing you'll yank your hair out over.

Dead Rising- "7 Day Survivor"

Are you ready for a mountain-sized zombie-killing task with minimal reward?  If so, you're ready for the "7 Day Survivor".  This 20-point Achievement is given to you if you manage to fight and survive your way through a seven-day mall jaunt filled with zombies – and this is without using a save, meaning you'll have to go through the game in one run.  Considering seven days in the game equates to 22 hours in real time – and that's not including meal breaks – you've got a lot of work ahead of you.

Call of Duty: Modern Warfare 4- "The Mile High Club"

Worth 20 Achievement points, the "Mile High Club" task sticks you with something that is pretty much impossible, unless you really, really know what you're doing.  You have to fight your way through a plane filled with terrorists on the Veteran difficulty, armed with only flash bangs and given a 60 second time limit.  So that means having to quickly run through the plane – without dying, natch – along with rescuing a hostage and escaping.  Very few have unlocked this, and for good reason.

Blazblue: Calamity Trigger – "Leonidas"

In order to even think about tackling this crazy 40-point Achievement, you have to be a true fighting master.  And we don't mean "local favorite at the arcade", we mean a DEDICATED player.  To win this Achievement, you need to beat Score Attack Mode on the pre-set difficulty, the toughest in the game.  The rounds have a pre-set time limit and round count, and the final four bosses you'll need to face – in ultimate forms – are cheaper than a scrounger at a dollar store.  Good luck finishing this mode.

Star Ocean: The Last Hope – "Ultimate Battler"

Ready to get REALLY pissed off?  Then welcome to the "Ultimate Battler" reward, which will only net you 10 Achievement points if you earn it.  The way to unlock it is by snagging up the 100 battle trophies in the game.  Some are easy at first, but others require utmost perfection to get.  The one that's bugging us the most requires you to get EXACTLY 55,555 points of damage – and considering some of the enemies you face, that's beyond easy. 

Dead Space 2 – "Hard To the Core"

50 points could be coming your way if you manage to complete this space quest on the toughest difficulty possible.  "Hard To the Core" challenges you to play through the game as Isaac Clarke in Hardcore mode, and you've only got three saves – with no checkpoints – in order to do so.  Run out, and it's game over.  But if you make it, you'll have the Achievements and the nifty Hand Cannon, complete with humorous sound effects.  "Bang, bang!"

Guitar Hero III: "The Inhuman Achievement"

So you think you're a rock god, and can take on any song that comes your way?  Well, in Guitar Hero III, you'll be put to the ultimate test, thanks to DragonForce.  All you need to do is get a perfect score of their song "Through the Fire and Flames".  On expert.  That's over 2,000 notes in a full multi-minute run, without missing ANYTHING.  And what do you get for nailing it?  15 points.  But, hey, some rockers are definitely proud to boast about it out there.  Won't you join them?

Left 4 Dead 2- "The Real Deal"

Think you can handle a zombie apocalypse?  And I mean REALLY handle one?  Then pick up a copy of Left 4 Dead 2 and put yourself to this test.  Set the game on Expert difficulty, than turn on Realism Mode, where enemies can take more damage (save for headshots) and you don't have the convenience of seeing your friends through walls.  You'll also have to face not having rescue closets to lean on, with only the Defibrillator to bring them back.  Survive this and 35 Achievement points are yours.

Rock Band 2- "Bladder of Steel"

Let's say you're not as talented enough to get the Guitar Hero III Achievement.  Well, here's the next worst thing – "Bladder of Steel".  To unlock this, you'll need to be playing a lot of Rock Band 2 – and we mean a LOT.  You need to run through the entire set list for the game in one run, without hitting the pause button at all.  That's a full seven-hour run, though some folks have earned it by having friends over for an all-night jam session.  Have fun with this one.

Gears of War 3- "Seriously, 3.0"

You know how Gears of War 2 put you through hell to make you earn the Seriously 2.0 Achievement?  Child's play compared to part three.  To earn this 100 point award, you'll need to earn all the Onyx medals with 6,000 kills for each of the game's weapons, while also earning MVP in competitive combat five times, snagging 1,500 enemy leaders as hostages, killing 6,000 enemies (500 rivals included), revive 1,200 allies (thankfully not all at once) and so much more.  Really, just poke around Epic Games' forums for a complete list.  It's truly the holy grail of Achievements, at least until Gears of War 4.  Seriously 4.0?!