It's hard to give up control. When we play a game we want to be able to exert our influence in every way possible to guide our avatar or team to the best possible outcome. With Anomaly: Warzone Earth, available now for Windows and Mac OS X, you have to give up much of that control. You can't select what enemies your units attack, or the speed at which they move. What you can do is plan their route through each level and offer some support in the way of power-ups. This is tower defense, but in this case you're not the one defending. Instead, you're the invading force, moving slowly but steadily toward the heart of alien-controlled ruins on Earth.

So how does it work?

At any point you can switch to a tactical view where you can see the entirety of the level and the enemies, and plan your route through the twisting streets. You control a character who moves on foot, following a series of armored units that drive along and destroy everything they see. While you can hit a button and speed up time, the game moves at its own pace, and missions can change in the heat of battle. It's your job to be aware of where you are, where you're going, and the safety of your units.

Anomaly: Warzone Earth pc*, mac Release Date: now * = platform reviewed

You help by using powers that can heal units, smoke screens that can hide units from enemy view, decoys that draw the enemy's fire, or by calling in airstrikes. You have a limited number of each of these to use, although more will be dropped onto the battlefield for you to pick up, and the rationing of the powers and their tactical use is a big part of your job. By planning the correct route and offering support for your units, you'll see victory. If you rush in without a clear plan or knowledge of what's coming next, things will go badly. Things spiral out of control rapidly once you lose sight of your objective.

The controls are simple to get used to, and you can play the whole thing from the comfort of your mouse. It's elegant and simple.

There are shifting battle conditions and enemies you can attack safely from different directions. You'll find power-ups that occasionally come in at a regular intervals and sometimes prove to be scarce. The difficulty level you choose has a lot to do with how the game plays, and those that feel cocky after mastering the game at the lower levels may be in for a bloody surprise at the higher difficulty levels.

At the tactical screen you can upgrade your units, choose their order in the straight line as they drive down the streets, or buy more to replace those that have fallen in combat. There is a high level of strategy in constructing your invading force; each unit is used in a different way and should be placed differently. You can only have up to six units at a time, and there could be more variety in the units you have to choose from, but for a $10 game, you'll find plenty of ways to lay waste to those in your path.

It's hard to argue with the price

All the nits that I could pick fall away due to the fact this is a $10 downloadable game on Steam and the Mac App store. There will also be an iOS version coming in the near future. The voice acting and writing is rocky, there is a grand opportunity for multiplayer that isn't explored, and levels can run a little long if you're hoping to make progress in a short session. But it does so much right that you'll have a hard time caring about that stuff. It takes a while to really get moving, but when the game picks up and you're juggling the acts of choosing your route, protecting your units, and making sure you're picking up all the powers that are dropped to help you... it becomes a beautiful, frantic mess.

This is why I love smaller, downloadable games: it's a lower investment to try them, and they often bring new ideas to established genres. Tactical and action elements are balanced well here, and if you're in the mood to sink a number of hours into a deeper-than-expected top-down experience you're going to fall in love.

If you want a few more thoughts on the game from our community, stop by the thread in our gaming forum, as there's a lively discussion going. There is also a demo available via Steam for both Windows and Mac OS X, so you can give the game a try if you're on the fence. If you're worried about your system handling this... don't be. I played it on my 13" Macbook Air. You have no excuses.

Verdict: Buy