Droids At The Gates
This is one good robot defense game. There are 15 gates where your enemies will try to brake your defenses. Defend each one and proceed to the next. You deep space base is of utmost importance for our presence in this part of the universe and it has to remain there. Make sure you save it from invasion or the repercussions will be great. Destroy incoming droids and use their parts to upgrade your weapons. Once they realize you can defend yourself, they will send even stronger units at you. Make sure you are ready and upgraded before that happens!