I really liked how it changed course midway through. It's been a while since I've seen it, but I wasn't expecting it to turn into a well-made slasher flick in space. Unlike most slasher films, however, this one had suspense because you cared about the fate of the characters, and there was a reason behind the slasher's motivation. Really good mix of theological/scientific interests too. I would give it an 8/10.
A mindless slasher is Jason.. Sunshine is not a mindless slasher. The killer had a purpose, as did the victims. Corazon's final moment, as the light left her eyes and she was left with a single plant rising from the ashes - was far too poetic to be likened to a machete to the jugular. Life will always find a way to prevail, in some capacity.