How do I play this exactly? Sanity/Light and Darkness - please explain

[DemonGhoul]

Basically, the game is meant to put you under pressure (I think).
Being in the darkness drains your sanity, with low sanity it makes the screen blur and Daniel is harder to control via the controls.
Staying in the light (tinderboxes or lantern) will help, and may bring your sanity up, though it makes it easier for monsters to see you.

In short, you must preserve your resources to stay alive.
I frankly never ran out -- maybe that's just because I was stubborn on using resources.