I KNOW SOMETHING YOU DON'T KNOW

One of the strategies that can make all the difference in the survival stakes is that of secret rooms and alcoves. They often conceal caches of ammo, medi-kits, weapons, or all three. It can be difficult to spot them, but not impossible.

Mindful that there are secret doors waiting to be found, you decide to press space...

...when suddenly, hey presto, a door appears. Aren't you glad you're alive.

What's that strange rippling over there on the left? If you're not sure, it's always...

...worth investigating. Because it might just lead to a precious little find like this one.