The Crystal Skip

The Crystal Skip saves a good amount of time over completing Crystal Man's stage, at the cost of not being able to collect the M tank or the Beat Letter within. As such, it is only useful if you intend to complete Castle stages (and bosses) without Beat, or you are in a no Castle Stages scenario (such as 46 Robots).

This strategy involves an intentional death, so make sure you have an extra life, even if it is Mega Man 5

Note the ball enemies do 3 points of damage, so Mega Man should have 1 HP remaining before taking the intentional death.

Arrow Setup

clear the 2nd and 3rd enemies after getting Mega Man to 1 HP remaining, then equip Super Arrow. You need 3 arrows.

From a standing position, fire one arrow to the right. Quickly jump on it, then fire an arrow left. Quickly jump on THAT, and fire a third arrow right. Stand on the leading tip of the arrow.

Mega Man should take a death, and the NEXT ball enemy should be missing its top half. Your respawn will take a very long time, but you teleport into the boss corridor.

Arrowless

What Even Happens?

This strategy kills Mega Man on the same frame another enemy spawns. This produces too many sprites for the NES to handle, overflowing the array of sprites on screen. Some of the data gets written into memory dedicated to Mega Man's X coordinate in tehestage, and the time until respawn. This sets Mega Man's position past the final checkpoint (in the boss corridor), making him respawn there. It also makes the respawn timer...large...so you have a moment to get a drink here.