The Last Shelter Mission 3 Guide
Mission 3 introduces Energy Unit. What it does is to extract energy so you can have constant supply of energy even though you have no beetles to kill to siphon their energy. Build these early on to amass energy to construct your defenses quickly. You can’t repair Energy Unit and Base except for Towers, so be sure to keep them well defended.
Mission 3 Final Layout
Mission 3 Playthrough