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

Submission #1122: JXQ's NES Moon Crystal in 08:53.0

Console: Nintendo Entertainment System
Game name: Moon Crystal
Game version: Japan
ROM filename: Moon Crystal (J).nes
Emulator: (unknown)
Movie length: 08:53.0
FrameCount: 31980
Re-record count: 7386
Author's real name:
Author's nickname: JXQ
Submitter: JXQ
Submitted at: 2006-07-15 18:03:42
Text last edited at: 2006-07-16 23:43:44
Text last edited by: JXQ
Download: Download (2294 bytes)
Status: decision: cancelled
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Author's comments and explanations:

Moon Crystal TAS by JXQ


This run satisfies the following criteria:

  • Aims for fastest time
  • Uses damage and death to save time
  • Abuses programming errors

  • Emulator Used: FCEU 0.98.16, last improved by Luke


NrgSpoon introduced me to this game. It's a gem of a platformer released only in Japan. The controls have some Prince of Persia in them, but are not as demanding. The music is great and the graphics are pretty good. I'm surprised the game was never ported to the US or Europe.

About the Game:

Since most will probably not be familiar with this game, here are a couple things worth mentioning.

There are treasure chests littered throughout each level. Most of the powerups are not needed in a TAS (such as extra lives, hearts, or heart expansions). There are two exceptions, however. One being the winged boots, which allow a mid-air jump, and the sword, which allows for a longer range and increased attack power on the original weapon. The increased attack power is only shown when life is down to one heart remaining. A jumping slash will then inflict three hits on bosses if aimed properly. This is why some levels take damage even when it may not seem obvious as to why.

Abuses Programming Errors?

It isn't noticeable when watching, but there is a jumping glitch used around frame 2465 (and several places afterwars). There's a point where jumping to a platform will change the animation to "standing", but not actually land on the platform. However, this allows a one-frame window to jump again.

Bosses have a peculiar way of telling the game when they are allowed to be hit again. If, after hitting a boss, you do something to cancel the sword-swinging animation, the "I can be hit again" flag will not reset until the sword is swung again. This is a nasty bug that makes jump-slashing during bosses a pain, but viewing the contents of memory location 061F allowed me to make sure every hit also made the next hit ready. This is more like...avoiding programming errors, I guess.

If death occurs after a boss is finished exploding, the game immediately jumps to the next cutscene about three seconds faster than waiting for the screen to fade out.

Points of Interest

Level 2

  • This is the only level where jumps boots are not required to complete the level. However, grabbing them saves several grabbing and climbing ledges, and also a couple screen transitions, so they end up saving enough time to be worth grabbing.

Level 3

  • The switches in this level open up gates shortly after for a brief period of time. You can hear them close after passing. (Clang)

  • Although a sword powerup would help against the boss, all the sword powerups in this level are too far off the main path to be worth it.

Level 4

  • The two hits are taken to reduce the life meter to 1, which allows for the powerful sword strike against the boss.

Level 5

  • Jumping is used often to avoid the turnaround animation when changing direction while descending.

  • The two hits taken save time themselves, and also put my energy meter at 1 to use the sword powerup on the boss.

  • I tried to take a final hit on the spikes above to save time after the boss exploded, but they are too high.

Level 6

  • Around frame 25400, the shortcut here I believe was not meant to be possible. The normal way is to go up and around the stairs to another room.

Ideas for Improvements

  • Level 1 - Boss strategy
  • Level 3 - Climbing branches
  • Level 4 - Take first hit while climbing second mast
  • Level 5 - Reduce lag by killing first gargoyle on 5th screen
  • General - Use better strategy for taking hit to avoid turnaround (see 26750)

Suggested Description & Screenshot:

Moon Crystal is a game that was only released in Japan. It features good controls that are reminiscent of both Prince of Persia and Ninja Gaiden, and being a late NES release, it has great music, graphics, and animation for its time.

The bosses of this game can be difficult due to a glitch that improperly resets the boss's vulnerability after being hit. You could say this run "avoids programming errors".

Good screenshot: Frame 7539.

Thanks to...

NrgSpoon, who (1) introduced me to the game, and (2) told me about the sword powerup ability.

JXQ: I have canceled this run and submitted an improved run which is 563 frames faster.

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