Tower Defense Heating Up

My first Game Jam. This is a Prototype of a Tower Defense in which you must defend your Engine. The Engine powers the guns and the guns create heat as they fire at the enemies. If the Enemies touch your Engine, they will heat it up more. You can pickup the Guns and place them wherever you think they best defend.  If your Engine Heat bar fills up,  Game Over. Pickup Coolant sources and bring them to the Engine to lower it's heat. 

Move: WASD, Sprint: Shift, Jump: Spacebar, Pickup: Mouse Left Click

Solo Developer. Started learning Unity 2 weeks ago but have past knowledge of other engines and programming.