Submission #5924: MUGG's GBC Survival Kids "game end glitch" in 02:45.70

(Link to video)
Game Boy Color
game end glitch
BizHawk 2.2.2
9897
59.7275005696058
1822
Unknown
Survival Kids - Kotou no Boukensha (J).gbc
Submitted by MUGG on 4/9/2018 5:25:42 PM
Submission Comments
Survival Kids is a game about a boy or girl who gets trapped on an island and tries to survive and escape. There are multiple endings in the game.
This TAS abuses the text glitch (aka. hut glitch) to reach Ending 3 and complete the game almost three minutes faster than klmz' published "Ending 1" run.

Objectives

  • Uses a game restart sequence
  • Abuses glitches in the game
  • Genre: Adventure

About the run

This game first caught my attention when I watched klmz' Ending 1 run a long time ago. I liked the gameplay and the fact different endings could be reached so I took a closer look at it. Eventually I began work on what would later be the Ending 8 TAS. While working on that run, I discovered a text glitch that happens if you bypass the trigger in front of the hut and then enter the hut.
Basicly, the trigger makes the text pointer (and ROM bank) a certain value, which makes the character say certain text and go enter the hut. Once inside the hut, more text is displayed. The game doesn't adjust the text pointer when entering the hut, but instead it assumes the text pointer wouldn't have changed between the two cutscenes, in front of the hut and inside the hut. Since you can bypass the trigger by pausing and restarting the game, you can walk around freely, allowing you to change the text pointer by using items or checking stuff on the overworld before entering the hut. After doing so, a wrong (and possibly glitched) text will be shown based on the erroneous text pointer and ROM bank. This glitch was long known about and tested thoroughly. Spikeman - who has been a big help in understanding Super Mario Land 2 Pause glitch - even jumped aboard the glitch investigation but we didn't find any uses in any of the three versions (US, EU, JP).
About two weeks ago, Melonslice kindly pointed out the glitch can be abused in the Japanese version, where the game's day counter is set to a seemingly random value without the game crashing. This only works if you are playing as the girl, for some reason. This way, having the day counter at 99 or higher and sleeping will trigger ending 3 or 7 (depending on whether the glitch makes it so the "other kid" has been found). It is also possible to complete ending 1 in some cases, since the game is made to believe the helicopter is supposed to arrive. I began investigation very quickly, and put my results in a google docs sheet.
Unfortunately, the Japanese version doesn't let you skip the intro cinematics. More differences are documented at TCRF.
The fastest way to beat the game seemed to be to reach ending 3 by eating a grass that triggers the "ugh, bitter" text, setting the text pointer to 16550 and ROM bank to 5. This resulted in a 20 second long glitch text (unlike most other results, where the glitch text would last for 1~2 minutes or longer). The name was set to のとの for no particular reason, because a short time needed to be spent waiting for the correct food scenario (so the "ugh, bitter" grass appears in the right spot). I chose this name because the kanji looked funny to me.
I would have loved for the glitch to allow me to complete the same ending as klmz, ED 1, reasonably fast. But the glitch didn't cooperate. It seems the fastest way to go for ending 1 using the glitch would be to use the Match item before entering the hut, setting the text pointer to 23019 and ROM bank to 3. This can cause the day counter to be set to 2, so sleeping once more will cause the helicopter to arrive magically. But the glitch text in this case is running slowly and it takes about 2 minutes until you regain control. Thus, ending 1 can be completed in about 4 minutes.
I've been asking myself, should each ending have its own run?
I don't think so. Not every ending has enough merit. You could argue that the glitch run should be its own category, but otherwise I would say there should be "fastest ending", "best ending" and "all endings". That's how I see it, but I will let the judges decide.

Possible improvements?

Someone on the Youtube comments mentioned they had figured out the possibility to take over the Program Counter (PC) and maybe achieve ACE, but they forgot to post about and document their findings. Perhaps there will be the possibility of a faster or better glitched run (such as "ending 8" or "all endings" in 3 minutes) at some point.

Thanks

  • Melonslice, for pointing out the possibility of a glitched speedrun.

ThunderAxe31: File replaced with a movie resynced on BizHawk 2.2.2, and judging.
ThunderAxe31: The text in the ending cutscene got broken, but the ending still counts as cleared since the game sets the relative completion flag after movie end. Accepting as improvement over the currently published fastest completion run.
fsvgm777: Processing.
Last Edited by adelikat on 10/25/2023 6:09 PM
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