And back in the corner of the free games, this time with Galactic Missile Defense, this time available on the site of Indiegala. Here is a synopsis of the title:

Galactic Missile Defense is an endless shooting / tower defense game with rankings where you have to protect the Earth from Martian invaders who declared war on our planet just because a space rover accidentally ruined their picnic! Three technologically advanced bases will allow you to keep the front line and unleash destruction on enemy ships. Answer the call immediately and defend the Earth in this battlefield of infinite possibilities!