This book has a different feel to it than Ender's Game. More is at stake this time around: the existence of the buggers is again put on the line, and the existence of the pequeninos is also at stake as humanity focuses on Milagre, the tiny human colony on the pequeninos' planet of Lusitania. Despite this, the plot is slower with less action; instead of battles in a space station, we get xenobiology and talking trees. It sounds weird, but Card makes it all work together perfectly. And the plot doesn't need all of the shoot-em-up action: it does just fine with the material it's got.
The characters this time around have changed as well. Our hero, Ender, is no longer a confused and frightened boy. Instead, he is an adult who has lived fifty years of his life in three thousand years. He is the respected Speaker from the Dead, not Ender the Xenocide anymore. We are met with an entire spectrum of new characters from the village of Milagre; instead of testosterone-laden teenage boys in the Battle Station, we see the Ribeira family and the challenges it goes through. Miro, Olhado, Ela, Novinha: they are so different from Ender's Game that they seem nearly disconnected at times, but that does not make this book any less good of a read.
Orson Scott Card's skill as an author has improved between the two books: Speaker for the Dead is gripping and has a more mature feel to its words. Though the content is no less dark or disturbing than Ender's Game, everything is more skillfully woven together. The questions of morality that pop up throughout this book are far more perplexing and interesting than those of Ender's Game. This book makes you think (that's a good thing). Thought-provoking sci-fi is an awesome combination.
Speaker for the Dead is a fitting sequel to Ender's Game. Don't let the three thousand year gap fool you — this book is definitely a continuation of Ender's Game, and heightens the tension in anticipation of the third book, Xenocide.