John is a Guardian of Earth, a superhuman being granted with immense powers from birth and trained by one of the oldest living aliens in the universe to defend humanity against all threats, both from within and from without. Together, they must face an unstoppable threat that could wipe out all life on the planet.
The plot is pretty straightforward, and everything boils down to the protagonist defeating the big bad aliens invading Earth. The first half is mostly about John reminiscing about his life and planning out contigencencies for the invasion, which is quite interesting since this is where most of the worldbuilding takes place—his powers, his training, even the history of the Guardians.
The characters are quite limited. But being the first book in a series, it didn’t really bother me. John, while sometimes annoying, is okay. His love interest barely made an impact on the plot. I found John’s mentor a little more interesting even though his character was not fully fleshed out.
The narrative is excellent, and I didn’t find the story boring. Fight scenes are good, pacing is okay, and the worldbuilding is interesting.
I only have two things which I disliked: first, some of the twists lack proper buildup, making them look like they just appeared out of nowhere without some context. Second, the ending felt anti-climactic. For a book titled Invasion, I had expected a grand battle between the protagonist and his enemies. Instead, we got what the book gave us.
But despite those flaws, this is an excellent sci-fi read.