X is trying to find the lost Maverick Hunter Zero, who has gone missing since X5. Of course, once found, Zero does most of the dirty work, while X is practically nowhere to be found.
This run completes all of the stages, showing off how nasty every level is on Xtreme difficulty. As always, Zero is much better suited to killing bosses than X. Zero also uses powerups that he wouldn't be able to use in an any% run.
The author, Rolanmen1, also improves the previous movie by 01:47.03 by taking a different route and using a new trick that allows him to skip the totem poles in Ground Scaravich's stage.
If you want to see the game completed as fast as possible, see the any% run.
Note: There are encodes of higher resolution in the discussion thread.