Yeah hero hp being high was a bit of a last minute addition as some other systems in the game couldnt be made in time. Ideally it would be a 3 life system where the hero gets stronger every time hes killed and the replacement health system due to time constraints is just balanced around the hero being killed in the final chamber so people can experience the game without it ending early
Green circle just shows all of the monsters in the monster cluster youve selected (you give commands to clusters rather than individual units)