Thank you for your feedback !
I agree the movement might be a bit confusing and we argued about different approaches but for consistency we believe it is the only way to make some kind of sense. It is basically a 1 dimensional movement wrapped in 2d space so holding down a direction to keep moving made sense but visually at some point the player would've been going in a direction opposite to the input and after playing many games with this control scheme, when your reflexes kick in to dodge something as you are upside down with inverted controls, you will press the wrong direction ^^.