as we level, and more energy is used to do missions. our energy reservoir is only at 25 energy (which dosn't increase as we level)....as you progress missions are costing 8-10 energy. Since the reservoir does not increase, today i only did 2 missions to the 10-15 i did yesterday when i first started. I would like energy reservoir to level up with us to help us with later missions. I haven't seen further into levels (educated guess), but im sure the cost to do missions are higher. maybe one energy per 3-4 levels that are compleated