Submission #2691: Randil's NES Kid Kool in 13:26.37

Nintendo Entertainment System
baseline
FCEUX 2.1.4a
48462
60.0988138974405
19099
Unknown
Kid Kool (U).nes
Submitted by Randil on 6/6/2010 7:30:08 AM
Submission Comments
This is my third subission of this game. It is 1276 frames, 21.27 seconds, faster than my previous run. The improved time comes from zipping through walls in 3-1 and 3-2, zipping through flagpoles on 5-3, better strategies on world 7, and more.
Most of the comments for this submission are copied from the previous run's comments, since they still fit very well, and because I'm too lazy to write new comments.
There are games that are fun to play but make for a boring TAS. Then there are games that are terrible to play, but make an entertaining TAS. In my opinion, this run is the latter. Kid Kool is a guy who can run very fast, and he has a furry ball named Wicky that he uses as a weapon. For some reason, enemies can't take getting hit by this soft buddy, so throwing him on enemies will kill them. This game is very similiar to the game Psycho Fox.
  • Emulator used: FCEUX 2.1.4a
  • Genre: Platformer.

About the game

The story in the game is that you have to collect 7 herbs in order to save the king's life. He need them for a certain medicine or something, I guess.
Kid Kool is, as stated above, in many ways a rip-off of Psycho Fox. The goal on each stage is simply to get from start to finish. Every third level there is a boss, who you kill by jumping on a pump until it hits the bottom. Sometimes the boss' neck is the pump. Yes, really.
The first thing you'll notice is that it takes quite a while for Kid Kool to accelerate to top speed. But once he has, he runs pretty darn fast. Keeping top speed throughout the whole level isn't always possible, but overall, I keep top speed throughout most of the levels. The most common reason for slowing down is to avoid bumping in to a wall.
Kid Kool can't accelerate during a jump, he maintains the speed he had when the jump was made during the entire jump.
Kid Kool can also jump on water, as long his speed is high enough. He can't jump on water if he lands on it after a jump.
You can jump on enemies, just like in Super Mario, however, enemies usually take several jumps to kill - they usually get pushed down into the ground by the first jump.
After each stage, there is a wheel of fortune type game, where you have a chance to get extra lives. You need to have collected sacks of coins in order to play this game, but obviously this would only waste time in a TAS, therefore I avoid all sacks of coins. The sacks are found in hidden boxes throughout the level (kinda like those hidden boxes in SMB).
Everyone who has played this game will learn to hate the air cannons. These horrible, horrible, cannons are mounted to the wall, ground or roof, and will shoot air puffs. These air puffs will push you in the direction they're travelling. These are the source of several slowdows in this run.
The furry ball that I pick up on level 1-1 is Wicky, your only weapon in this game. You throw him at enemies to kill them, and after a while, he comes zooming back to you. You can not deal damage to bosses with him.

Some comments on this TAS

This run is 1276 frames faster than my cancelled run. The improvements come from zipping through walls in 3-1 and 3-2, zipping through flagpoles on 5-3, better strategies on world 7, faster boss fights, and some other minor improvements. Almost all levels have been improved.
TaoTao told me that someone named narimasa had uploaded a run on the (J) version on nicovideo here, and that run used many nice strategies that I didn't consider. It is much thanks to that run that this run turned out this fast.

Zipping through walls

By ducking and jumping towards the ceiling, there are a few frames where Kid Kool's head is inside the block above him. The game's response to this is to push him out horizontally in the opposite direction. If you change your horizontal speed during these few frames you are inside the block, you will get pushed out "forward". Even if there is a block in your way, you will get pushed into it. This is the core of the trick - by getting pushed inside the wall, you can jump up so that you're above the screen, and from there run to the end of the level.
I used Matlab to find out the best way to perform the wall zipping. Performing the zips is quite tricky, and you must set up your X and Y subpixels just right. I had Matlab help me some to find how high of a jump to make, and how to move to perform the zip.
The flag pole zipping works pretty much the same way, but you only need to turn around so you're not facing the flag pole when you bump into it. You also need to hit it low enough. If this is done correctly, when you bump into the flag pole, you acutally move inside it slightly, and the game will push you out of the flag pole on the other side.

Other comments

Here I'll comment on things that might look odd or that I think need commenting:
  • The way the pump works on boss levels is quite complex. There is a timer that decides when you can jump on the pump again, and this timer will only increase when the pump is not moving. The pump moves whenever you touch it, so you don't want to stand on the pump more than necessary.
  • Wicky can be used to stop bosses from moving. In particular, by throwing him against the right wall while the boss is close enough, he will continuosly damage the boss, making him stand still while I can focus on jumping on the pump. Note that this does not actually damage the boss, the only way to deal damage to him is to use the pump.
  • I manipulate luck (kill the boss on a specific position) to make the herb move to the right when it appears on screen. Where the herb appears depends on the boss' X and Y position when he dies.
  • On level 3-3, the boss can't be held in the right corner because he would cover the pump.
  • The "running backwards" trick on 3-1 is only a visual trick, and neither saves nor wastes time.
  • If I run back a bit at the start of a level, it is to gain a bit more speed before a jump.
  • Kid Kool can't run on sand without slowing down, so I avoid doing so where possible.
  • I could have ended input earlier and still beat the game, but I aimed for reaching the ending sequence as fast as possible, and ending input earlier would cause me to reach the ending sequence a few frames later.
The rerecord count is a bit messed up due to a lot of editing. It should be fairly close to the real value, though.
Thanks to:
  • narimasa for his run.
  • TaoTao for telling me about the zipping trick and narimasa's run.
  • Sonikkustar for encouragment and looking through the run.
I hope you enjoy watching this run!
Trivia: This run synchs on the (J) version of the game too, so it is comparable to narimasa's run.

Truncated: Randil has asked me to replace his movie. The new one is 146 frames faster. Randil's explanation of what is changed:
The only change in this new movie file is that the wall zip in level 3-2 is done at a better place.
FractalFusion: Accepting as it is both well-done and entertaining.
Velitha: Processing....
Last Edited by Velitha on 6/20/2010 10:11 PM
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