Perimeter is a great game if you have some time to spare. The Unit building is unique. You have to build the base units, then "transform" them into more advanced units. This idea is a new twist on making your army of units like in other games. Although i wish it wouldn't take so many base units to make 1 advanced unit of a particular type. The idea of having a shield around your base whenever you need it is cool, but it uses too much power and is hard to keep going for any amount of time. For those of you looking for a "new' RTS experience, you should pick up Perimeter. It's a great game with an interesting little story behind it.