Hints for conserving ammunition:
* Play on normal, and just use the axe for most kills.
* Use the rifle if you have to(good for dogs), and the shotgun if necessary(deals much more damage than the other two guns).
* You can use Lab A and Lab B to "ring around the rosie".
* Ignore the enemy that spawns in Lab A after turning on the generator by going around and closing the door behind you.
* Enemies can be lured outside or into rooms and locked away.
* Running backwards while slashing with your axe is a good strategy for taking down enemies.
* If you've gotten quite into a run without wasting bullets, consider saving in case you mess up. That way you don't have to reload and do everything from the start again.