This game either takes place after X5 or X6...or at the end of the X series EITHER WAY it happens sometime after the X series. The Zero series is my fave series in the Mega Man franchise but holy shit this series is very very hard. The world now has a new entity called Cyber Elves and they help with just about anything. Ciel, a young scientist, awakens Zero from his sleep as she's being chased by Neo Arcadian forces who are killing her friends along the way as they fight back. He finds out that his aged long friend X is retiring innocent reploids and has become rather tyrannical. With his 4 X Guardians and their subordinates carrying out his rule and policy, Zero must shake off the dust and cobwebs and fight his way to the truth. The game is stupidly hard-rather, its damn hard if you are trying to 100% the game. Like many sonic games, this game ranks you on your performance but that's where all the frustration comes from. Most games I know rank you per level and leave it at that. This one wants to rank your overall game performance over ALL THE LEVELS YOU'VE BEEN PLAYING. So if you get an S rank on the intro mission, cool. Your averate rank is S. Do 1 level after that and get a B Rank, then you're overall game rank is A. Rank isn't TOO big an issue in this one but using the Cyber Elves, which give you heart tanks, energy tanks, defense boosts etc etc like a typical X game will PERMANENTLY lower your rank. Getting some of the game's unlockables require you to beat the game with an A or S rank overall. THAT'S hardcore ._. Once you get all the unlockables, which requires you to FIND all Cyber Elves and NOT use a single one...then you can go nuts and use them all. But on your first playthru, you're probably just trying to enjoy the game and will of course use a few. Then wonder why, even when you did your best, the game gives you shitty rankings. The gameplay itself is fantastic but again, hard as hell. One of my faves in the series is the first one but its also one of the hardest Pick it up if you want a hard Mega Man game though