A very solid tactical strategy game that puts you in charge of an anti alien organization. It mixes well mamagments phases where you'll have to think how to best use your resources in order to get better and improve and a combat tactical phase where death is permament. The really strong point of this game is how easy and uncomplicated this is, while retaining a certain level of depth. Enemy Within changes up the tempo of the game a lot and makes for a better, more erratic first months.
The real letdown is the inverse difficulty curve that becomes more apparent the more you go on in the game.