Instant Transmission

Instant Transmission, previously referred to as Instant Transmission Kick, is 's and, formerly, Super Saiyan Goku's up special move in Super Smash Flash 2.

Overview
When performed, Goku flips backwards with a kick before teleporting a short distance in the direction inputted by the player at the time it is used, or he will teleport in place if no direction is held. If an opponent is close enough to Goku when hit, they will take 7% damage instantly move directly to wherever Goku reappears after teleporting, where he will deliver a follow-up kick that deals 7% damage and considerable knockback. If Goku hits an opponent at the end of the move, opponents will not be grabbed, instead, will be sent upward with weak knockback.

As the name implies, the move has fairly little startup lag and almost no ending lag, as well as intangibility frames during the teleportation. However, it covers a relatively short vertical distance (though this can be countered if Goku still has his float time and double jump), and Goku will be left helpless after the move ends unless the follow-up kick is delivered.

Kaiō-ken Goku's version of the move is nearly identical to Goku's version, though the initial kick instead deals 14% damage, and the move is slightly faster.

Super Saiyan Goku version
Super Saiyan Goku's version of the move was very similar to Goku's, although with some different properties: It travels a shorter distance, but also does not cause helplessness and can be performed repeatedly in the air. The kick deals 10% damage, with less knockback, and opponents hit cannot be moved directly to where he reappears.

By holding or pressing the special move button, Super Saiyan Goku will perform a kick upon reappearing, and if held longer he will follow up with a strong punch downwards. Both hits deal 10% damage, with the kick dealing weak forward knockback and the punch being a strong meteor smash.

The attack got removed alongside Super Saiyan Goku in Beta 1.2, when Meteor Combination became Goku's Final Smash.

Origin
Instant Transmission is a technique in the  franchise that debuted in chapter #336 from the original Dragon Ball manga, titled "A Three Year Gamble". One of Goku's signature moves, this technique allows him to instantly teletransport from one place to another by locating someone else's ki. Goku was taught this technique by the people of Planet Yardrat while he was training there after his battle with Frieza on Planet Namek. To locate someone's ki, he usually puts his index and middle finger on his forehead in order to concentrate. It can be used to travel really long distances (such as going from a galaxy to another), to go from from the living world to the Other World (where the souls of the deceased go after death) and vice versa, and even to travel outside of time (as shown in Dragon Ball Xenoverse).

While this technique is primarily used by Goku as a means of transportation, he has also been shown using it for combat, such as when he instantly teleported in front of Cell in order to hit him directly with a Kamehameha. In SSF2, it is also utilized this way at the middle of Meteor Combination, in which Goku teleport before he uses the Genki Dama. Functionally, Instant Transmission in SSF2 is most similar to an attack Goku uses at the end of a grounded combo in the game Dragon Ball Z: Budokai Tenkaichi 3, in which he kicks the opponent upwards and uses Instant Transmission to catch them with a kick forwards.

Trivia

 * In v0.9b of the SSF2 Demo, there was a bug that caused Goku to fly very far after executing Instant Transmission as Kaiō-ken or Super Saiyan finished, often leading to a self-destruct or giving Goku an immense extension to his normal recovery.