Cool idea! The movement cost seems to be wildly inconsistent though. Sometimes I can move across the whole level without using any energy, and sometimes just moving half a square uses up all my energy. If it could be more clear when and why energy is being used up, that would be really helpful. You need to be giving a bit more feedback to the player about their actions so they can understand where they went wrong and improve.
(if you have time to check out our game, that'd be awesome)