Spartan is a simple strategy game which I found easy to pickup and play and quite enjoying. But do not go into this expecting great depth; it is simply a good diversion for an hour or two (though campaign games can take ages to complete). There is demo for this game (or its expansion/sequel Troy), so you can try before you buy and the demo is pretty representative of the full game.
All in all a great distraction (and look for the Troy expansion, which adds to the fun), but only if you can get it cheap (~10 euros or so).