Each time I juice up my shmups people remind me the point is to see the projectiles and dodge them and not to overwhelm the player with distractions.

The video example is very over the top, going to that extent in a difficult precision based game probably would be distracting. 

However, that doesn't mean there aren't ways to add more juice to the game without being distracting.

Particle effects can be very over the top, but used sparingly they can help convey useful information

Quality sound effects, such as having subtlety different sound effects for different enemies/attacks, are probably one of the best ways to add polish and engage the player into the world around them. I've heard of fighting games that are quite accessible to blind people from this type of design. 

Having shapes morph to show movement I imagine also isn't too distracting. Honestly, I can't pretend to have all the answers myself, but the best advice I can give is don't underestimate the power of subtle but nuanced effects.