What indeed was that?
I like to think I'm pretty generous with my ratings, but that could very easily have been a lot better.
You could make it again, but with a lot more stars, a greater buildup and some plinky-plunky music. You could have a pan across a sea of stars, then fly forward through them, like the classic Star Wars hyperspace effect. Then as you (the viewer) are floating through this animated space, boom!
Same thing happens, but without the extra eyes and mouth behind the eyes and mouth. And yes, it should have been louder, but not necessarily a lot louder.
Basically, it's always a fun idea to have a shock moment in an animation, but this one could have been better with very little extra work.