Rockman X2 makes a particularly interesting run as many of the weapons can actually be used in mobility, such as a grappling hook, a fast mid-air dash or even a weapon that can make enemies into platforms. The author (parrot14green) takes special care to ensure that when there is a situation in which a weapon would help him progress quicker, he uses it.
This run improves the previous version by about 15 seconds of game-time. Other time savings are the result of using the Japanese version of Mega Man X2 (Rockman X2).
In order to get the shōryūken (flame uppercut) which is used towards the end of the movie, the author must first collect 100% of items, such as Heart Tanks, Sub Tanks, and Item Capsules, but not Zero Parts. However, because these powerups are not far out of the way, and because the shōryūken saves so much time later on, this movie may also prove to be as fast as possible.
The page Mega Man X Tricks explains some of the tricks that can be used in the X series games.