The following list shows what you will notice when paranormal activity is close. Use this to prepare for any frightening scenes up ahead.
If the an enemy does not know you are there, holster your weapon and melee the guards. If you are lucky, the fallen guard will make little noise, and they will not look at you when you do it. You can dispose of the most of the guards without firing a shot.
Use the following tactics to defeat groups.
Pistols can easily defeat nightmares. They can take them out in one shot, compared to other weapons that require multiple shots (except heavy weapons). This is also very useful, due to the fact that certain times when Alma and Fettel take you to hell, you will lose all weapons and get a pistol.
When you find some ammunition, drop the corresponding weapon. Collect the ammunition, then pick up the weapon again. You will gain more ammunition than if you had only collected the ammunition by itself.
In the harbor mission, you will find plenty of consoles with "Power and shutdown." There are however, one or two machines that have wording similar to "Coins collected, secrets found, lives spent, ammo used, etc.". It is a gamer's console.