That is until you place your lights, of course. Each level has a limited set of lights which you must strategically place around the level in order to illuminate your path to the exit. The challenge isn't over once you've got your lights in the right place, however. The platforming itself is a different challenge of its own, offering awkward jumps and varying traps that you will not be able to navigate safely if you have not lit up the level correctly.
As there are no specific light locations, each one of the 20 levels have their own unique solution that you will create as you play. If you're not particularly efficient with your lighting then you may be forced to run through a section of a level completely unaided with only hope (or your memory) to save you.