Ammo: This shows how much of each type of ammo you're carrying and the maximum amount you could carry.
Key Cards: You can see any keys you possess right here.
Armor: Your armor helps to protect you as long as it lasts.
This is your mug. When you're hit, your face looks in the direction from which the damage came. Also, as you take damage, your face begins to look like raw hamburger.
BFG 9000s.
Plasma Rifles.
Rocket Launchers.
Chainguns.
Shotguns / Combat Shotguns. Pressing the "3" key will toggle between the Shotgun and the Combat Shotgun.
Fist / Chainsaw.
Arms: If the number above is highlighted, the corresponding weapon is available and you can choose that weapon by pressing the number on the keyboard.
Health: Percentage of health remaining (0 to 100).
Main Ammo: The number of shots you've got left in the weapon you are currently using.
