Tool-assisted game movies
When human skills are just not enough

Submission #2482: sgrunt's NES Metroid "low%" in 11:45.46

Console: Nintendo Entertainment System
Game name: Metroid
Game version: USA PRG0
ROM filename: Metroid (U) (PRG0) [!].nes
Branch: low%
Emulator: (unknown)
Movie length: 11:45.46
FrameCount: 42397
Re-record count: 7919
Author's real name: SJM
Author's nickname: sgrunt
Submitter: sgrunt
Submitted at: 2009-12-06 14:52:24
Text last edited at: 2009-12-06 22:02:24
Text last edited by: sgrunt
Download: Download (6150 bytes)
Status: published
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Author's comments and explanations:
This is an improvement of 268 frames (4.5 seconds) over Zoizite's old low% run (from 2004). 64 frames of this is due to not using a password, for an effective in-game improvement of 204 frames (3.4 seconds).

Many of the tricks and strategies new to this run were first used in TAS form by Lord Tom in his any% and 100% runs.

Game objectives

  • Emulator used: FCEUX 2.1.2
  • Aims for fastest time
  • Collects one item
  • Takes damage to save time
  • Uses a game restart sequence
  • Abuses programming errors in the game
  • Manipulates luck
  • Uses no passwords
  • Colours two dinosaurs (and one disembodied brain)


This is a low% run, which collects only the Maru Mari. In the absence of bombs and an ice beam, the only way to gain entrance to Tourian is by killing the minibosses, which also grants 150 missiles - more than enough to handle the Zebetites and Mother Brain.

As with the old low% run, I target Ridley first. Although it's been discovered that Kraid is accessible without missiles (see the any% run for an illustration of this), it is faster to navigate the hideout with missiles, and also significantly faster to get to Tourian from the entrance to Kraid's hideout than the entrance to Norfair.

For those unaware, pushing Up+A on the second controller while the game is paused sends you to the password screen which normally follows a game over, from where the game continues in its current state from the last elevator used; this saves significant amounts of time in this run (and other runs).

The other significant time saver is the door glitch. It is possible to stand in a door as it closes, causing Samus to become stuck in the doorway; in this state, morphing and unmorphing repeatedly causes Samus to ascend quickly inside the wall. When in a vertical room, passing the top of the screen this way wraps Samus around to the screen below, out of sight; however the screen does not follow completely, and in order to exit through any doors Samus needs to get back on to to the screen. Apart from this run, this glitch is used in the old low% run and the any% run.

There are two reasons I decided to create this run - Metroid is a game that I enjoy seeing played, and the present low% run is very old and suboptimal (as a matter of fact, it's a run from 2004, which I view collectively as having a bounty of sorts on them).

Stage by stage comments

Brinstar, round 1

The first improvement comes as early as the third room, using a strategy similar to the 100% run. Destroying the first two Skrees (such that they don't drop items - this is important later) causes another Skree closer to the tunnel to appear, and a Zoomer which normally appears in or near the tunnel to not appear, so there's no need to wait for it as with the old run.

There's a very brief delay exiting that room to manipulate subpixel position and allow the jump past the second Ripper in the vertical shaft. By sheer coincidence, this bit of manipulation caused the Zoomers on the left side of the shaft to be in position to manipulate item drops from them, which I decided to make use of for later damage boosting.


The most notable snippet here is the door glitch, used to access the lower half of the far right vertical shaft and so reach the entrance to Ridley's hideout without needing bombs.

Leaving the second room, I get hit by an off-screen enemy. I was unable to manipulate this enemy to disappear.


Unlike Norfar, off the start I have more favorable enemy positions, allowing greater speed through the first room. I don't need to manipulate a drop from the Zebbo in the vertical shaft because I already have an extra 5 energy units from earlier.

Annoyingly, in the Multiviola room, the second set of Multiviolas after the hallway spawned two Multiviolas instead of one, so I can't kill the one from atop the pillar as in the previous run. The strategy I use instead still lets me get the energy drop and nimbly avoid the second Multiviola.

Ridley, as expected, is a pushover.

Brinstar, round 2

Here's the second use of the door glitch, using Lord Tom's improved jumping strategy from the any% run.


Testing revealed that taking the conventional route to Kraid (with the benefit of missiles obtained from Ridley) is somewhat faster than use of the door glitch as illustrated in the any% run (on the order of 100 frames). I had initially expected the door glitch to be faster, but it wasn't. (Go figure.)

Kraid is rather uncooperative, but some deft maneuvering allows for a quicker Kraid fight than the old run (and it looks more impressive, too).

Brinstar, round 3

It's nearly impossible not to get item drops at this point. This is a sticking point in the first horizontal room in the segment - because one of the first two Skrees will drop an item, the Zoomer near the tunnel will appear. Fortunately, killing the Skrees causes it to be moving away from the tunnel rather than into it, so there's no need to wait for it again.

Also, optimising jumping is annoying.


This is simultaneously one of the most entertaining parts of the run (along with the first part of the Kraid fight - in a low% run you don't have the means to kill the Metroids, so one simply has to dodge them as best as one can) and the most aggravating. Where one is incapable of killing the Metroids, the biggest factor affecting speed is lag due to the huge number of sprites on the screen; lag management is therefore key.

93 missiles are required to complete Tourian without killing any Metroids - 20 for the doors, 40 for the Zebetites (8 * 5), and 33 for Mother Brain (1 to break the tank tank + 32). I enter with 96 - the three extra missiles go towards Metroid dodging.

Directly entering the second room caused an unfavorable Rinka pattern - that is, Samus would die immediately upon entering the room. The input immediately before is to manipulate the Rinkas into a pattern that is avoidable (this took a while when creating it).

Mother Brain quickly becomes an ex-brain. The door glitch consistently failed to work correctly for whatever reason, though I come up with a just-about-as-fast alternative, and the time on the escape shaft is 865. (I guess this means I get a "meh" vote from Lord Tom...)

Other comments

Suggested screenshot: frame 38000:

It just wouldn't be right for an encoder to submit a run without an accompanying encode. Therefore, you can download the encode from archive.org here, or watch on Dailymotion here.

(Another version of the encode calling it a low% run in the subtitles is here, DM here.)

Occasionally the run will desync during the second horizontal room in Norfair (the room after the first door glitch). If Samus gets hit by a Nova and ends up at 15 energy, you are about to see her jump into the lava in frustration of that jump not going as it should have and should try watching the run again.

The listed re-record count is probably slightly low; there were several instances where I edited the input directly and didn't always remember to update the counter afterwards.

There's probably the odd frame that can be shaved here and there, but Metroid is notoriously hexing/splicing-unfriendly and it would be a huge headache to try to do so outside of the context of a new run.

I'd like to offer my thanks to Lord Tom, Zoizite, and Arc for their past Metroid runs, which were a huge help as a reference for the creation of this run, and to you, the TASVideos community, for taking the time to read these comments and watch the run.


Nach: Nice improvements to an existing run. Accepting.

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