If you have not played this game, and are a "new strategy" fan because of XCOM or Fire Emblem, you absolutely have to play this. I sort of don't really want to get into the details, as many above me have, and I sort of don't like to talk about the specifics of something I find so special, as I feel it sort of gets in the way of your possible enjoyment and surprise. Please, if you have a Playstation 3, or have someone who you might borrow one from, try your hardest to get a hold of this.
It's the game that paved the way for XCOM and older style strategy games to make their comeback. Play this videogame.