It could be totally remade with new level designs (still side scrolling but like longer or even additional levels), new fighting system to implement new attacks and special attacks, finishing moves, Super-Ultra-Mega-3D Zord Boss fights (not in side scrolling fashion but full 3D), and more. (Maybe even an in-cockpit mode for the Falconzord where you can fly around the baddies and shoot them down with your missiles (MULTIPLAYER! While you fly around in the Falconzord your buddy can be on the ground using the Megazord!))
I can so totally see this.
Or even better. An original game with the original rangers made in similar fashion to this one. :O --- Nostalgia Insane Mode: http://www.youtube.com/watch?v=Xaenj5GuMaM#t=0m30s