Ender´s Game (2013) is a movie based on the book Ender´s Game by Orson Scott Card (*).
The movie adaptation by Gravin Hood focuses on the first of five books that Tor Books has published in the Ender Epos.

Ender´s Game is a military war thriller:

In the future, an alien race called the Formics attacked humanity with one of their fleets. Even though humanity wasn’t prepared we were able to defend ourselves against the aliens.
Since that day the Formics didn´t come back but Humanity is preparing for the day this might happen.
For this reason, the smartest children train at a military school to become fleet officers and strategies.

Ender is the brightest mind among the cadets. His ability to adapt faster to unknown surroundings and to process data quicker than adults separates him from the others. Enders superior Hyrum Graff (Harrison Ford) promotes Ender to the higher military ranks. There he has to train to be commanding the whole human fleet in the final warfare against the Formics.

Gravin Hood’s thriller skips a complicated backstory and focuses on his main character ender, who can be seen as a symbol of mankind.
His inner conflict tears him between an over dominating, violent side and a world of emotions on the other hand. Both sides are symbolized by his sibling who didn´t proceed with their career at military school for different reasons.
As Homo Sapiens Sapiens has shown in the past, Ender tends to defend himself to a point where he not only won the war but defeated his enemy for good.

Ender´s Game focusses on humanities biggest fear:

As Yuval Noah Harari puts it in his book A Brief History of Humankind, human beings are sheep with nuclear destructive power.
Human beings have not been on top of the food chain for millions of years. We have stood and crawled in the shadow of more powerful and stronger creatures until we managed to use the power of our minds to build weapons and to develop strategies. Even over thousands of years of human history, humans still don´t know how to cope with the power we have given in to our own hands.

We are fearful creatures who strive for safety and security against a more powerful species. And for history not to rewind we will destroy whatever might oppose the slightest threat to us.