When performing the Happy Spring, Miles "Tails" Prower thrust himself upwards with a spring in midair to gain extra height, extending his hands and legs outwards with a look of happiness on his face.
In gameplay, this move is useful for reaching areas above that are otherwise difficult to get to (without flying) and avoiding falling into gaps. In addition, it will not cancel the momentum Tails receives from the Boost Mode. Happy Spring cannot damage enemies though, and using it leaves Tails open to harm. Also, like most of Tails' other Mid-Air Trick Actions, this move tends to make Tails lose momentum when he lands. The Happy Spring can also only be pulled off after Tails has been launched into midair by gimmicks like the Spring or Ramp.
Sonic Advance 2
Happy Spring made its debut in Sonic Advance 2, alongside other Big Air maneuvers. To perform it in gameplay, the player must press up on and the R Button at the same time after being launched into midair by gimmicks.
Sonic Advance 3
In Sonic Advance 3, the Happy Spring is again Tails' Big Air maneuver, and one of his Special Actions. In this game, Tails can only use the move when having Sonic the Hedgehog as his partner. To use the Happy Spring in gameplay, the player has to press up on and the R Button at the same time after being launched into midair by gimmicks, just like in Sonic Advance 2.