In Notrium you will experience a real time universe in which you need to survive. A strange planet is your temporary home, as you crashd your spaceship here. You need to get home alive and for this you must use different alien objects that can be found on the planet. This is how you can create different gadgets and weapons.
Notrium is similar to Robinson Crusoe, only timed differently. You can build a gun in order to fight aliens, but you must not forget about the food and shelter that are necessare in order to survive on this strange planet until you find your way back home.