Rasengan Smash

Rasengan Smash was originally thought to be Naruto's down special move in Super Smash Flash 2, instead, it was replaced with the Kage Bunshin, and was turned into his down smash in Version 0.5 Alpha of the Demo. Naruto uses Rasengan and then smashes the ground with it. According to flash2dojo, the closer opponents are to Naruto, the more damage this attack would have dealt.