Nintendo Power%
In Nintendo Power%, you must collect 35 specific items in order. At the end of the run you will have 6 Energy Tanks, 55 Missiles, 10 Super Missiles, and all major upgrades besides Wave Beam.
Overview
Brinstar
In Brinstar, you'll grab all the items you grab in Any%, plus Long Beam.
Escaping the pre-Long Beam room the way you came in is fastest, but it can be a little tricky. To hit the last block, you need to fire a shot on the same frame that you morph. The beam projectile spawns slightly lower if your timing is right, so use that as a cue that you should continue rolling right.
Crateria
From Norfair, head to the left and enter Crateria, grabbing the first Unknown Item, the Missile Tank, and Power Grip(11). Then, return to Norfair.
Norfair
Head straight to Ice Beam, ignoring the Missile Tank you pass on your way. Grab the Missile Tank(12) above Ice Beam that you would collect in Any%, then take the Ridley shortcut at the top right of Norfair.
From there, break the missile block above you, dodge the Missile Tank, take the ball cannon, and return to Brinstar.
Brinstar
Go all the way to the top of the first tall shaft you come across, and take the door on the right. You will come across a room with a lone Waver. Break the crumble blocks above it, and climb to the top of the room, using either Ice Beam or infinite bomb jumps.
Wait for the bugs to destroy the barriers, then take the upper route across the room. You will need to do some bomb jumps to reach the penultimate ledge, since we don't have Hi-Jump. Open the red door and grab Varia Suit(14). From there, head into the acid below and grab the Energy Tank.
From there, head down towards Kraid's lair, stopping on your way to grab the ceiling E-tank(16) in the first Chozo hint room.
If you aren't full on missiles, either heal at the Chozo statue or farm in Kraid's lair.
Kraid
Once in Kraid's lair, head to the red door on your right and make your way to Acid Worm, grabbing the Missile Tank and Energy Tank on your way. After defeating Acid Worm, grab the Missile Tank(19) at the bottom-left of its room.
Grab the Missile Tank(20) on your way out from this section, then head to Acid Worm Skip room and take the zipline across.
In the next room, bomb the floor and head straight down to grab the second Unknown Item(21).
If you want to conserve missiles for the rest of Kraid, you can opt to jump over the sidehoppers on your way to the Kraid fight.
After defeating Kraid, you should ideally have at least 10 missiles, which you will need to defeat the Reos in the acid moat on your way out. If not, farm Kraid's drops, or, worst case, heal while grabbing Speed Booster(22).
Brinstar & Norfair
Upon returning to Brinstar, head straight to Norfair. You may be tempted to grab the Missile Tank in the shortcut on your way to Norfair, but don't.
In Norfair, start running from the left door of the elevator room so you can get a speedboost started by the time you reach the big room, then shinespark across. Maintain your speedboost into the next room and break the speed blocks to fall below.
From there, head left, and once you reach halfway between the two Polyps, start running right so you can charge a speedboost in the next room, to break the speed blocks in the floor.
Once below, head left two rooms to grab our next item, Hi-Jump(23). You may want to heal at Hi-Jump if you have less than the 18 missiles needed to defeat Imago Coccoon. Return to the main Norfair shaft, jump up, and grab the Missile Tank(24) on your way down, then head to Imago Coccoon, then into Ridley's lair.
Ridley
Ridley's lair is much the same as Any%, but with one small detour: fighting Imago immediately after entering. You're probably low on missiles, so you'll want to farm in the room to the right of the elevator room before heading up. With Imago defeated, grab your first Super Missile Tank(25).
Head back into Ridley and grab all the same items as in Any%: the Missile(26) & Super Missile Tank(27) in Multiviola room, the Missile Tank(27) in pillar room, and Any% first Supers(29).
After passing through the sidehopper room, fall straight down and grab the third and final Unknown Item(30), followed by the Energy Tank(31) behind it, then defeat Ridley.
Once Ridley is defeated, head right and use speed booster to defeat the enemies in Speedway, collecting the drops if your ammo is low. In the next room, break the hidden block in the floor and grab the Energy Tank(32), then head back to Norfair.
Norfair
Head immediately right after the elevator and go to the bottom of the next room, taking a left. Charge a speed booster to destroy the blocks in your path, and either shinespark or use the ball cannon to head up to grab Screw Attack(33). From there, take a right through the heated room and return to Brinstar.
Brinstar/Tourian/Crateria
Tourian is much the same as Any% - try not to get grabbed by Metroids. Try to keep yourself to a minimum of 4 Supers, to minimize farming in the Rinka room before Mother Brain.
After Mother Brain is defeated, escape and proceed to Suitless.
Mothership
Chozodia
Once Charlie is defeated, be careful to avoid the underwater Super Missile Tank behind speed blocks. Instead we'll be grabbing the Super Missile Tank(34) hidden in the lava.
As you make your way to Mecha, take a detour to the bottom-right of FUNgineer jump room to grab the Super Missile Tank(35) hidden in the wall. From here, don't grab any other items and head straight to Mecha Ridley and escape.