So erm...I think this is bad design.
I've only put in like one minute or less into the game but felt I should state this.
To elaborate more as the screenshot doesn't really show, these things fire wave shots that have tall range and are really fast. Due to the shields, and the height of the waves hitbox, you can only really shoot them when they fire and they do a lot of damage and they both fire at the same time so..yeah.
I thought the same until I realize the charge shot pierces the shield. Kind of weird though.
Does this game save by the way?