Zeb Skip

If you're already familiar with Super Metroid's Zeb Skip, there is a similar concept with a similar result in Zero Mission. The biggest difference for Zero Mission is the trick is much harder and with a smaller return on investment.

There are 4 zebitites in the Mother Brain room, and each one takes 7 missiles to destroy. With the optimal ammo of 50 missiles and 4 supers missiles, you normally would destroy the first two zebitites, go back and refill in the previous room, and then come back with just enough ammo to destroy the last two zebitites and defeat Mother Brain.

If you perform the zeb skip, you don't have to destroy the first one and the third one doesn't spawn, which means you enter the room with max ammo and don't have to refill because you only destroy the 2nd and 4th zebitites.

The way to perform the zeb skip is to run into the room and immediately drop to the floor and hug the left wall. Freeze the rinka that spawns in the wall so that it doesn't touch you and knock you around. You'll see a rinka come at you from the top left of the screen, jump and freeze it at a point where the top of the rinka is barely above the floor. I don't yet know the exact window for getting this correct, but if the rinka is too low and lower than the floor than you can't stand on it for the next part, and if the rinka is too high and way above the floor, you can still get the hover state in the next part but you won't clip through the zebitite.

Once the rinka is frozen, refreeze the rinka in the wall next to you so that it stays frozen longer and gives you more time to do the trick, and then run up and jump onto the rinka you froze in the platform. You need to place a morph bomb high enough that it doesn't kill the rinka, but still low enough that it will make you bomb jump while you're morphed on the rinka. Some people do a spring ball to set it up, I personally do a normal jump and a mid-air morph because that works in the 9% category where you won't have springball.

This is the hard part, you need to unmorph on the same frame the bomb explodes. If you unmorph and never move, you did it too early. If you see the bomb push samus off a ground a little bit before you unmorphed, you did it too late. If done correctly, you'll be in a hover state where Samus's legs are dangling underneath her. (You can practice this on any frozen enemy in the game to get in this hover state). While hovering, hold left and you should slide right through the zebitite.