GiN has reviewed Tyranny:

Being Bad is so Good in Tyranny RPG

Most role-playing games either make you the typical good guy, or give you some sort of choice as to how you want to play your character. However, I am sure that we have all found that even in those games where there is a choice, the so-called good paths are often much more scripted and fun to play. Obsidian Entertainment’s Tyranny tosses all of that out the window. You are a bad guy in this game, working for an even more corrupt government and enforcing their laws by any means necessary.

[...]

Tyranny is a refreshing twist for the old RPG genre. Beyond just the fact that you can truly play an evil character if you want, is a really solid game that hits all the right buttons. The plot is really well crafted. The character all seem realistic. Combat is fierce but fair. Player choices truly matter. And there is a ton of replay value because one or two choices can totally change the world, making subsequent playthroughs almost feel like completely different games.

Good and evil players alike should find a lot to love in Tyranny, one of the best RPGs we’ve played all year.