If you try to read Earth Unaware as a stand-alone book you will be disappointed. It ends seemingly in the middle of a great invasion of earth. There is an entire subplot about ultra-special military commandos that has absolutely nothing to do with the main plot.
Yep, this is obviously the first in a series. From the
author's web site, the sequel has been completed for sometime, but is just waiting for a later release.
This is also geared at fans of the Ender series. We get the first look at the "Formics" and their invasion of earth. We also view a young Mazer Rackham. He would later go on to be a mentor and an important figure in the formic wars in Ender's Game.
The story in this book centers around a "free mining" ship that is mining an asteroid. They happen to spot something unusual in the distance that looks like an alien spacecraft. However, they just sit on the information. It just so happens that some evil corporate types want to test some of their weapons by blowing up the same asteroid. They bump the miners off the asteroid, destroying their communication equipment and hurting a miner in the process. The miners are now drifting through space, trying to rendezvous with another ship. However, when they get there, they find the ship is destroyed. They hunt for survivors (and find a few). They also have a live encounter with some of the formics. Now, they really need to tell the world. To do so, one boy goes back to the moon in a cargo ship, while the main ship eventually hooks up with the evil corporates and some "nice corporates" to try to battle the formics. They are not successful, with one ship destroyed and the others leaving. Eventually, the boy (Victor Delgado) makes it to the moon, but gets caught in bureaucracy. He tries to post the "alien video" on the nets - but we are shown lots of "fake video" making it seem unlikely they will succeed.
The book centers primarily around Victor. However, the most interesting character is Lern Jukes, the nominal captain of the corporate ship. He is the heir to the corporate fortune. However, he does not feel respected by his father. He wants to show a successful mission. However, he is constantly torn between doing what is "right" and what will bring "corporate success". He finds himself often justifying behaviors that he knows are "wrong". Yet, he has difficulty bringing out a full justification. He is upset that the crew seems to disobey his orders, often killing people or letting men die in the name of his safety. (However, it usually turned out that if they wouldn't have done that, everyone would have ended up dead.) In the end, he discovers that he is not even in control of the ship - his father had set up the security officer as the one ultimately in control.
All in all it is a good "first act" of a thriller. There is not a whole lot of "deep meaning" here. For the first part in a trilogy, there are not a whole lot of loose ends. (It seems the formic ship does a good job of blowing away potential loose ends.)
I wonder how much of the book was by Card, and how much by Johnston. My gut says "This is Card's Universe", so Johnston probably wrote the majority, with Card only helping out to give it some credibility. I can see him saying. "Yo! Scott! This Ender movie is coming out, and you have people hungry for more, and you are stuck creating new universes. Here is my idea for the prequel. You make some edits and lets release it." Card then rewrites a few sections and the book fits in with his style and it gets released in a hurry.
It does fit well with Card's style. I like almost everything that he has written, but love very few. He is a good "safe" author. I'm not likely to be overly disappointed. While I read plenty of science fiction in the 80s and 90s, I never read any of Card's SF work. However, at the time, I had known of him well, and read many of his works. I remember a Mormon humour book and a few good articles in Commodore 64 computer magazines like Ahoy! It wasn't until a few decades later that I heard somebody mention "Orson Scott Card" as one of the science fiction writers they really loved. Hmm... (However, the person wasn't somebody that I tended to have common tastes, so I brushed it aside until later.) Ender's Game was ok. It wasn't awful, but didn't drive me to read more. However, Speaker for the Dead was great, and that got me on the whole kick.
At the end of the Earth Unaware audiobook, there is a brief interview with Card. He mentions that he is a huge fan of audiobooks. (I share that with him.) He also mentioned that his favorite authors are Jane Austen and J.R.R. Tolkien. (I definitely don't share that with him. Those are the two most sleep-inducing authors I have attempted to read.)
The Hive is the second book in the second Formic War series. This is yet another "Ender's Game" book. Card has really milked his seminal work for all it has. (Though it would be nice if he would actually finish some the series that he has left hanging, such as Alvin Maker.) There are a number of subplots floating around. There is the pirate who gets captured by the Formics and is then used as a science experiment. (I could just see this going bad.) There is the young married couple zipping off separately in space to help with the war effort. Then there are the military people. We have a lunar refugee crisis. And then there is bureaucratic incompetence. A central theme is that military and political people can be good, but most of them have their own motives that are not necessarily in the best interest of the organization as a whole. Chain of command can often separate those with needed information from those that act on it. The "hegemone" seemingly knows everything. He and his song both have the best interests of themselves and the world at heart, though they sometimes seem corrupt. They also seem to magically know exactly how things are going on. The "good guys" always seem to have just a little more brains and intuition than would be humanly possible. The book also devolves at times into long political episodes before picking up again. It wraps up a lot of the key plot points, but leaves open plenty more for the next book.
I didn't realize this series of books could fit in the Endger's Game timeline. I had thought that the first Formic War was immediately followed by Ender's Game. However, there is the matter of Mazer Rackham having been traveling through space to be able to talk with Ender, so I guess it makes sense. This books feels like the previous Formic War series. There are some people that see what is going on. Those with power don't believe them and dilly dally until it starts to get too late. Most leaders are greedy and really in it for their own benefit. They feel threatened by people that are more capable precisely because they are more capable. The "heroes" are crazy smart, but suffer from self doubt and can be a little bit too humble. (And how is it, that the Aliens always happen to be near mining ships that know how to identify them?) Mazer is ignored and in trouble with the military. Young Jukes is working hard and tries to do the right thing, but not ruthless like his father. Victor can fix anything and is brave enough to go into space. His fiance enlists in the military and soon finds herself in command of their now commandeered mining ship. Everyone seems to understand the political reason for their actions - except for the politicians themselves.
Ender's World is made up of a number of essays about Ender's Game. Most are by literary types describing how the novel impacted their lives and writing career. Interspersed with the essays are some short Q&As and other short bits from Card providing details on the book and his writing process.
Two gung-ho youth bankrolled by a billionaire's son infiltrate an alien ship and make a plan to defeat it. Through the help of a crack military team (MOPS), they are able to go back and use the ship's weapons and some A-team type ingenuity to defeat the alien formics. 
This is the second of the Ender's Game prequels. Very little attempt was made to make this book "stand alone". It starts with the attempted warning of the Formic invasion and continues on with the invasion, ending on a cliffhanger with an attempt to stop the Formics.