I dont see why so many people are whining about the difficulty curve or difficulty... Im already on level 2.5 with no problems on any levels, and it only took me about 15 mins... I love the diversity of units and buildings, definitely allows for more then one way to beat each level :)
lol, i was surprised when i beat the last level, i didnt feel a difficulty curve at all through out this game, but it was very creative. the last level was simple, and i thought i had just finished the easy levels. overall, great game :D