Pet: Constructobot

 is a pet that reduces construction costs of base items and rooms. When building with deployed constructobots, a great deal of build cost can be saved. For that reason, it is mostly adviced to build bigger bases and expensive equippment with constroctorbots. This includes upgrades on expensive base items (such as generator, bubble shield, shield generator, automated gun turrets, etc.) and also upgrades on the very expensive Drill Platform.

Build cost can be further decreased through the engineer jobs passive skills (lvl 30 Room construction cost reduction and lvl 50 base item construction cost reduction).