Submission #6152: chatterbox's SNES EarthBound in 54:07.83

System Super NES Emulator BizHawk 1.13.2
Game Version JPN Frame Count 195191
ROM Filename Mother 2 - Gyiyg no Gyakushuu (Japan).sfc Frame Rate 60.0988138974405
Branch Rerecord Count 57461
Unknown Authors chatterbox
Game EarthBound
Submitted by chatterbox on 11/17/2018 6:44:25 AM

Submission Comments
This run improves the previously published TAS by 56483 frames thanks to the newly discovered two glitches, feedback from EarthBound TAS pioneer, pirohiko has also been applied. It's also important to note that the Japanese version was inevitably used for several reasons.

A new glitch

Both of the glitches described below were discovered by pirohiko.

Overwriting sprites

The game can hold up to 22 sprites on a single screen from slot #00 to slot #21. But if it exceeds 22, the sprite in slot #00 will overwrite the 22nd sprite. This glitch was performed in the following sequence of steps:
  • Manipulate the sprite so that the rightmost barricade is accessed to slot #00.
  • Create 10 enemies and fill all the slots.
  • Then the sprite present in slot #00 is overwritten by the 22nd generated sprite.
Before barricade was overwritten, there were a number of sprites like this:
It was used to get rid of the barricade of the Onett that block the way to Twoson. Moreover, pirohiko devised a way to overwrite the Urban Zombies that block the stairs from Threed to Saturn Valley. Ultimately, the reason we're bringing Jeff into the party is to use the cold-induced stairs glitch. If he doesn't rescue Ness & Paula and doesn't build stairs, there's nowhere else to find that. That's why he invented the new route, however, he reacted vaguely to whether it is feasible. I'm not sure yet how we're going to get through countless enemies and head to the stairs. So I didn't think much about this route, I pursued Jeff joining the party.

Another wall clip with a Skip sandwiches

Taking a Skip sandwich speeds up the character by 1.5 times. At this time, if you keep pressing the ← and ↑ buttons in turn against the slanted wall, the x and y subpixel are gradually reduced by the multiplication arithmetic error, resulting in the player moving slowly through the wall and slightly to the top left. It was usefully used in Jeff's part at Winters.

Version choice

I absolutely wanted to keep working on the English version, but unfortunately, it seems that overwriting sprites glitch had been modified on the English version. The mentioned glitch is accomplished by forcing the sprite present in slot #00 to an arbitrary slot by exceeding the maximum number of sprites that can be displayed on a single screen. However, in this English version, the sprite present in slot #00 flickering repeatedly to prevent the sprite from being pushed to arbitrary slot. On the one hand, the Japanese version is much faster in text than the English version. When Ness leveling up with the enormous amount of experience he gets after defeating Ness' Nightmare, you can see a marked difference in the speed of text.

Possible improvements

There's one thing left that inaccurate. Under the assumption that overwriting sprites glitch is available in Threed, I thought there would be no way that Ness could defeat Ness' Nightmare on his own. Yet after a little investigation that it turned out that using a couple of Bag of Dragonites would kill off all of Ness' Nightmare's HP. Using Bag of Dragonite, it'll inflict 800 +/- 25% damage on an enemy (same effect as PSI Fire); Ness' Nightmare is only affected by 75% of PSI Fire damage. So the effect of Bag of Dragonite is actually 600 +/- 25%, we need at least three Bag of Dragonites to defeat Ness' Nightmare which has 1654 HP. One of them can be found in the Magicant, the other in Fire Spring, and the last in Scaraba Pyramid. Perhaps, given the amount of time we spend looking for Bag of Dragonites, there may not be as many improvements as expected.

Suggested screenshot

Frame 27067

Memory: Claiming for judging.
Memory: While at first glance the optimization looks ok, it in fact lost time to a previously known WIP of the game. While the timesaves aren't anything super big, it is really questionable submitting when there is another WIP of the game in progress that is faster by gameplay and I cannot find that acceptable. According to the Movie Rules, a submission must beat all known records. This sometimes includes unfinished WIPs.
This run uses the Japanese version for supposed exclusive timesaves but in fact are not exclusive. The two versions of the game shall remain free to obsolete each other.

Last Edited by Memory on 12/2/2018 7:07 PM
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