GD Legends Finale by OmegaFalcon | Geometry Dash 

One of the most amazing autos I've ever seen created for this game, I truly feel this is the closest we've ever gotten to a Geometry Dash Movie, the quality is oozing out of this, the art is incredibly clean, and while it isn't over the top or extremely detailed, the real stars of this are the effects and the animation especially.
OmegaFalcon uses almost all of the effects the game has to offer to tell a story, and uses them in such a way that you can feel the weight of the story, you can feel and see the power of the boss and the attacks coming from both sides, obviously inspired by anime fights, Dragon Ball especially, with the beams and power ups, the flying etc.
Something else that I thought was a nice addition is the blood and bruises, unexpected for sure, adding a shock factor to the animation, but it makes you care about the characters, to the point where you start rooting for them. Overall an amazing auto level, definitely one of my favorites of all time.