[TAS] Space Invaders arcade: Shooting invaders in reverse order

Channel:

Prog61

Subscribers:

10,000

Published on March 4, 2020 2:31:17 PM ● Video Link: https://www.youtube.com/watch?v=KvH4rdfAwCY

Game:

Space Invaders (1978)

Duration: 1:54

1,893 views

28

Tool-assisted superplay (TAS) of Space Invaders arcade: Shooting invaders in reverse order

The goal of this TAS:
-Shooting the invaders from the top down

I did this TAS to verify the rumor on http://www.digitpress.com/eastereggs/arcadespaceinvaders.htm that state:
· RUMOR: Leave at least one of the bottom invaders (either the first or second) in each column. This means shooting around them to destroy the others above them. Nearly impossible, but it can be done. What happens is, if you destroy all but at least one of the bottom two row invaders in each column, the invaders stop marching. They become sitting ducks. You can then blast mystery saucers to your heart's content. Both SI and Deluxe SI have this trick. {Brian Deuel}

Since the top invaders are 4 pixels less wide than the other aliens, it is impossible to shoot them before the others (at the beginning). When an invader move, it move 2 pixel, so you can shoot the alien above him for a few frames but the top invaders are unreachable. The number of frames depend of how many invaders has to move before the one you want to shoot move. When all the invaders are there you have a window of 11 frames to shoot.
Play this video frame by frame you will see what I mean. On PC use the 'greater than' key to advance one frame at a time. If you see 2 invaders move each frames, you are at 30 fps, switch to 720p60 in the quality setting. At 1:10 I shoot a bullet that miss a top row invaders to show you that I cannot shoot him.

To be able to shoot a top row alien, it has to move 2 times (4 pixels) before the bullet reach him. Since the bullet take about 12 frames to go pass a bottom invader to a top row invaders, it mean that it is possible to shoot a top invader only when there is less than 12 invaders total. With this TAS I verified that I could not shoot a top row invader until there was 10 invaders remaining.

So I believe that this Myth is BUSTED.

Go to https://en.wikipedia.org/wiki/Tool-assisted_speedrun for more information on Tool-Assisted Speed-runs
or http://tasvideos.org for more video.

Other Statistics