Blue Aliens are melee enemies in Notrium.
Blue Aliens come in two varieties, Small Blue Aliens and Blue Aliens. The Small Blue Aliens have very low health and don't do much damage, whilst the large Blue Aliens have more health and deal greater damage.
Blue Aliens are melee enemies and will chase you down if they spot you to get in melee range.
Small Blue Aliens drop a Small Blue Alien Corpse which, if used will restore 4 hunger. Larger Blue Aliens will drop a Blue Alien Corpse, which can be used to upgrade Power Armor or eaten to restore 10 hunger.
The corpse of the larger Blue Aliens can be used to upgrade Power Armor into Enhanced Power Armor.