The sok ngat, an uppercut-style elbow strike used in Muay Thai. It can be used repeatedly as fast as the player can press the attack button, which allows it to chain into itself and lead into many of Ryu's moves for a quick finisher. Despite its appearance, it has decent range.
An uppercut. Strong for its speed and grants his upper body intangibility from frames 4-10, making it a surprisingly effective anti-air attack and KO move.
A lunging side kick. Moves him slightly forward and has the highest range of all his standard attacks, as it is able to hit opponents two character lengths away from him. However, it has noticeable ending lag.
A legsweep. Launches opponents at a diagonal angle and unlike most down smashes, it only hits in one direction. Has the fastest start-up of all of his smash attacks, with more range than his up smash but less than his forward smash, making it also his safest smash attack at a distance.
A downward, fast angled cross. Hitting an airborne opponent with the attack's sweetspot will meteor smash the opponent, while hitting an airborne opponent with the sourspot launches the opponent diagonally upward with high knockback.
A stretch kick transitioned into an axe kick. It can combo into an aerial attack at low percents. While the axe kick cannot hit the thrown opponent, it can nevertheless hit another opponent that is too close to Ryu. Unlike the stretch kick, the axe kick deals much more damage and has high knockback.
Steven had showed some of Ryu's sprites on his DeviantArt page years ago. The animation was removed weeks after, however.
His trailer which included Goku and Lucario was a reference to their fighting origins. Goku, like Ryu, is a martial artist while Lucario is a "fighting" type Pokemon who can learn fighting type attacks and various martial arts.
In the Super Smash Bros. Brawl mod, Project M, Lucario received some of Ryu's moves in the Street Fighter games for its moveset, like the Shoryuken for its up smash, and Tatsumaki Senpukyaku for its neutral aerial.