All upgrades add cash.
Your mission in this strategy game is to survive battling hordes of hostile creatures on a distant planet for 5 long days. You'll gain brand new weapons and support as you battle through each day. Enemies who get past your defense will damage the Life Support. When this reaches zero, all hope will be lost.
Use YOUR MOUSE to place units. Use 1-6 NUMBER KEYS to construct weapons/use support power. Press SPACEBAR to cancel placement. Press "W" KEY to start wave. Hold "E" KEY to view firing lanes. Use "R" KEY to recycle weapon. Good luck!