Thanks for playing! The multitasking is definitely meant to be the main source of difficulty, so we imagined that a successful player would find ways to reduce the multitasking requirements: typically by controlling all 3 like you did, or sometimes by leaving 2 to cover some directions while controlling a single Hecatia. We wanted the players to get a taste of how difficulty it'd be to have three bodies, so that they can better appreciate how awesome Hecatia is.
Basically – you got it! Congrats. :D