I think Armada suffers the same problem that plagues Go Tell a Watchman (well, one of them anyway... it doesn't suffer from the whole questionable publication situation). Ready Player One was an outstanding debut, and did magnificently well even with catering strongly to specific audiences. In comparison, Armada is almost derivative and unpolished.
Both stories feature young men on the brink of adulthood, an unashamed love of 80's pop and geek cultures, and feature video games as central plot vehicles.
On it's own, Armada suffers from some proofreading errors, things that a decent editor should have picked up. Namely the following really stood out: people shaking hands... then shaking hands again the next paragraph, or leaping up while in a seat harness, or calling a dodecahedron a d10. For the last one I just need to quote the Phantom Tollbooth "my faces are many, my sides are not few, I'm the dodecahedron, who are you?" Dodecahedrons have 12 sides folks. 12.
But I enjoyed the story, even with it's literal deus ex machina. It's lighthearted, fun, and unabashedly geeky.