when aliens take over earth, Retired Vietnam Veteran, Cliff Wells sets out on a mission to bring his missing grandson home. along the way Cliff recruits a group of unlikely heroes to help him rescue his Grandson, reunite his family, and save the planet from. The Cosmic Crustaceans.

it's Red Dawn meets Independence Day, meets war of the worlds.

https://www.amazon.com/dp/B0BZMYH7YB