Mega Man X4/Walkthrough

Game Flow
The main game is played in the following order:
 * Start Sky Lagoon as the intro stage.
 * Return to base and get to choose Maverick stages in any order.
 * After completing any four stages, the player is forced to visit Memorial Hall.
 * After defeating all Maverick bosses, complete Space Port, and Final Weapon (twice in different parts).

Suggested order
Before checking below, please check above on the chart.

As X
The levels can be chosen in order and there are a lot of ways to accomplish the completion at the easiest ways possible. keep in mind the following:
 * The Jungle has the Leg Upgrade that brings advantage to mobility.
 * Be cautious of defeating the 4th Maverick of your choice. After you complete 4 of the 8 stages, not only will you be unable to select levels, but you are forced into a boss fight with no walls and must defeat it to proceed. Its weakness is Frost Tower.

As Zero
Two of Zero's "weapons" actually are skills that deal no damage, therefore the Maverick order has to be different.

The regular Z-saber deals slightly more damage to Web Spider than to most other Mavericks, while Slash Beast is the hardest boss, even with all other powerups.

This order may be challenging since you need to defeat Magma Dragoon first, which is hard even with Ride Armor. However, it also ensures that the stages do not need to be re-visited (or up to once, in case two of the hearts are too hard to get without Kuuenbu).

In case someone is trying a "No miss" run, starting with Marine Base (Jet Stingray) is also good, since it is a bike stage and easier to crush into walls.