DOOM Eternal

• The game is designed around you using most of your equipment/abilities regularly. You'll have abilities that help replenish ammo, health, and armor. You're expected to use these when you run out of those things, though obviously there are pickups in the levels as well. One example is that you'll regularly run out of ammo in a firefight and be expected to chainsaw smaller enemies to get more back.

• While you unlock Fast Travel near the end of stages, it isn't permanent - it just lasts until you exit that level. If you skip a collectible and want to go back at a later point, you'll have to replay the level entirely.

• Within a level, no collectables are "missable" - you can always fast travel back to them at the end of the level. Some events will lock off sections of the map, but you can always fast travel around them once you unlock it.

• In single player mode, you can repeat any level with all your acquired weapons and upgrades. It's best to do this in between levels because you'll lose your progress in the current level when you do it.

• You don't need to complete a level in order to save any upgrades, collectibles, weapons, completed challenges, etc. that you find. They're saved to your profile immediately upon acquisition. This is most relevant if you're replaying levels for things you missed.

• There are no collectibles that are reliant on upgrades that you'd get in a later mission, so whatever mission you're on you should be able to get 100% of everything without having to come back to it later.

• The Master Levels are meant as "end-game" content and I wouldn't bother attempting them until you've got every weapon/upgrade and know how to take care of every type of enemy. You will get introduced to enemies, upgrades, and weapons gradually in the campaign, whilst in a Master Level they just throw everything at you at once. You have been warned!

• If you don't want to sign up for a Bethesda.net account, you can force the game into offline mode. Use the "Windows Defender Firewall with Advanced Security" application to turn off the connection specifically for the Doom Eternal EXE. When you run the game, before it loads, you might get a message saying it could not contact the servers. If you click the "Next" button it'll load a web page in your browser and ask you to paste a code into the dialogue box to authenticate.

• Higher difficulties do not affect the number of enemies, just how dangerous they are. You can adjust the difficulty mid playthrough.