At an enemy garrison, disable its barrier inside and try keeping a few soldiers alive. Use cyber hearts to get a Blood Dragon into the base. Allow the remaining soldiers and Blood Dragon to fight each other and, while they are fighting each other, get ammo, health, and other supplies from the garrison's vending machine. After the Blood Dragon has killed all the enemy soldiers, it's health should be lower. Use C400 and grenades to whittle down the Blood Dragon's health some more while using the structures in the garrison to block its beam attack. If necessary, get more health from the vending machine. When the the Blood Dragon's health is brought down to just a sliver, switch to the bow. Be patient and wait for the dragon to rear back and fire an arrow into its chest. Repeat the process until its dead.
While playing the "Desperately Saving Susan" Nerd Rescue, go to coordinates X: 479.1, Y: 488.3 to find a Xenomorph egg from Alien behind the nerd you save. What's cool about this is that Michael Biehn, voice actor of the main character, was also a cast member in Aliens.