I'll just point out that the thing I didn't like about enders game was that the book felt too monotone. It has a great twist at the end, but everything leading up to it is linear, predictable, and while initially exciting, quickly becomes uninteresting.
Personally, having read it at an early age, I found the science part of the sci-fi to be very captivating and philosophy to be interesting.
From a sci-fi historiology perspective, you can see parts of the Bradbury style space-as-wild-west, while also some of the Gibson-esqe interconnected computing. I also found that the philosophy of the ansible to be related to some of Philip K Dick's warped sense of reality books.