Submission #5274: ThunderAxe31's GB Rolan's Curse "game end glitch" in 04:23.40

Console Game Boy Emulator BizHawk 1.11.8
Game Version USA Frame Count 15732
ROM Filename Rolan's Curse (USA).gb Frame Rate 59.7275005696058
Branch game end glitch Rerecord Count 1911
Unknown Authors ThunderAxe31
Game Rolan's Curse
Submitted by ThunderAxe31 on 10/29/2016 1:28:30 AM

Submission Comments

Important note (read before voting)

The game completion time is apparently longer due to more accurate emulation, which makes the loading times longer, but gameplay is actually shorter. For anyone who doesn't know: using a better emulator even if this means to apparently increase the time of the run, is highly recommended by the rules of the site.
Here is a VBA-rr version of the submission movie, made by me before migrating to BizHawk, which shows game completion 22 frames shorter than the current publication:
This also explains why the rerecord count is so small.

Submitter's encode

About the game

Rolan's Curse is a Game Boy hack 'n slash stabbing game in which you take the role of Sir Lagsalot a knight that has to defeat an evil lord named Barius, in order to free the land of Rolan.

Game mechanics

The gameplay is very similar to The Legend of Zelda, but slower and simpler. You start with a sword, an attack power of 1 and 4 HP (2 hearts). Attack power and HP can be increased temporary or permanently by different items; temporary increments will disappear after you kill a boss and proceed to the next chapter (there are 4 in total) and permanent increments will stay for the entire play. You can move in the four cardinal directions for steps of 8 pixels (half map tile) and attack enemies by using an equipped weapon. Killed enemies may drop a potion or an armor; in rare cases other items. Here is the list:
  • "Weapons": Are to be used by pressing B button. When you pick one of these, it will replace your current weapon and increase your temporary attack power by 1.
    • "Sword": Can attack only withlin 8 pixel in the direction the hero is facing.
    • "Wand of Uzi": Looks like a rod with a jewel on the top. Can attack at distance; attack rate and power seems to be the same as for the sword.
  • "Special Items": Various items set to be used by pressing A button. Then you pick one, it will replace the one you already have, if any.
    • "Potion of Life": Looks like a jug. When used, refills HP completely and disappears.
    • "Shield of Valor": A shield with a cross on it. When you hold A button, it will protect frontally from ranged attack, but not contact. If you use the D-pad while you still hold A button, the hero will turn but not walk.
    • "Magic Axe": Looks like a pickaxe. Can used to remove some obstables.
    • "Chameleon's Ring": A ring with a jewel. When you press A, you the hero will turn into a background object and become immute to enemy contact until you press A again to come back normal. This doest not protect from ranged attacks and you can't attack while transformed.
    • "Power Crystal": Looks like an orb. To use it, you need to keep A until charged, then release. Does more damages than other weapons, but seems useless due to being slow.
  • "Other Articles": These items take effect in the moment you pick them up.
    • "Chain Mail": It is supposed to be an armor, but looks like a mushroom to me. When picked up, it increases your HP temporary by 1 (half hearth).
    • "Merlin's Cloak": It is supposed to be a cape, but looks like a slice of watermelon. When picked up, gives temporary invulnerability to any attack.
    • "Elvenade": Looks like a vial. When picked up, restores 4 HP (2 hearts).
    • "Heart": Guess what? Gives you a heart. Permanently <3.
    • "Gauntlet": Looks like a... hand. Increases attack by 1 permanently.

Game objectives

  • Emulator used: BizHawk 1.11.8
  • Improving the current publication's completion time
  • Takes damage to save time
  • Major skip glitch
  • Final boss skip glitch
  • Heavy luck manipulation

Known tricks

  • Taking damage: well, this is more like common sense; you spare a lot of time by not attacking and in the meantime you take the healing items you need for not dying.
  • Luck manipulation: most enemies can drop an item if they are killed in the right moment. There is a 2-byte value located at C0A3 which is relative to the moment the killing blow is dealt (first frame in which the sword is visible). This value changes every non-lag frame and it is not affected by any action; however if some unknown requirements aren't met, the drop won't occur. Apparently, the amount of enemies killed before seems to be involved.
    • (not used) It is possible to wait before entering an area, if this makes the enemy killing less problematic, like at frame 5968, in which you can't wait even a frame before killing the enemy, otherwise you will get hit by the enemy incoming from the right.
    • (new) If you have have enough spare HP and the RNG allows it, you can walk into the enemy to save walking time. Used at 12982.
  • Quick hitting: sometimes is possible to execute the next attack faster. This is probably due to a bug; more research about this may improve the run by some frames.
  • Controlling enemy spawning: some enemy spawn only if an other given enemy is killed. This can sometimes used to actually prevent an enemy spawning. This is used only once in the movie: if at 4052 you don't kill the bat, the other bat won't disappear in the right moment.
  • (not used) Attacking from the corner: if you change direction when you are near a wall, the hero will turn without having to take a step. This can allow to quickly turn for attacking an enemy from behind a corner, for enemies like at frames 6512 and 10693.
  • Quick turning: it is possible to invert direction during a step. This allows to pick up items and turning for attacking in a different direction, without having to make a full step. Used at 13021 and 14334 for items and at 15285 and 15354 for attacking.

Game end glitch

If the killing blow is dealt to the first boss in the same time the player's HP goes to zero, the game will mistakenly think the last boss is actually beaten. In order to do so quicker, the player is provided to have enough HP to walk into the boss and not die on the first contact damage. Otherwise, it would have to wait for the boss to resume moving, which would waste a lot of time.

Improvements done

The movie is mostly the same to the current publication, except for two improvements I made at:
  • 7867: 1 frame saved by killing the ghost without touching it.
  • 12982: 21 frames saved by walking into the enemy instead of waiting in front of it and picking up the potion by quickly inverting direction two times.
  • 15730: 1 frame saved by optimizing the last attack. not really...

Possible improvements

  • Maybe it would be possible to save a significant amount of frames by avoid killing one or two enemies. This is a problem because most enemy drop don't occur if you omit one or more kills. More thorough research of the item drop mechanism may uncover new ways to improve this run. Here is a run recored with VBA-rr in which I managed to save even more frames, until I got forced to lose them all for the last potion drop:
  • The same goes for the attack rate: sometimes is possible to attack faster, probably due to a bug. Note how the second attack to the wolf at 8625 is 4 frames slower than in Aqfaq's run (first publication). mmbossman (author of the current run) also noticed this, but was unable to solve the problem. Optimizing this exploit may save frames for any situation in which it is needed to hit an enemy multiple time, like for that wolf and the boss. It may even allow to kill the lizardman at 12718, which would result in not needing a potion.

Suggested screenshots

13011 or 13020


What's next

While I may be able to improve this run in future, my main goal is to make a 2-players glitchless run out of this game. Rolan's Curse is probably the only adventure GB game which implements real-time multiplayer capabilities, and I'm sure it would be very interesting and entertaining to create and to watch. Read the relative forum thread for more info.

Note for the judge

I wrote on the forum that using BizHawk would result in a different RNG, but I was wrong. I found no difference in gameplay while making this run, except for the boss fight, in which I had to change the timing of a couple of attacks because of lag, but this didn't result in more frames. So in the end this run is longer just due to loading times.

Samsara: File replaced with a 1 frame improvement.
Masterjun: Judging with energy!
Masterjun: File replaced with the old movie, as the 1 frame improvement movie didn't finish the game.
Masterjun: Total time is longer due to emulator differences. However this movie still improves the previous run. Accepted to the Vault as an improvement over the previous movie.
fsvgm777: Processing.

Last Edited by fsvgm777 on 11/13/2016 10:11 AM
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