The Facebook game drops you onto a mission map in outer space, where there is currently only one planet to explore (more will be added in the future; in fact, there are already place-holders for at least four more planets). This first planet is Cerberus Prime, a T.O.O.L. stronghold. You'll need to start a revolution on the planet, with each individual revolution being comprised of different levels or waves.
Once you start a level, you'll find that this isn't any ordinary Facebook game, as it's as action-oriented as they come. You'll have two control configurations to choose from, either moving your Gun Bros with the arrow keys or the WASD keys, as in many popular PC games. The mouse is used to fire your gun, and you can even use the Space Bar to auto-aim your weapon, if you're not used to this type of potentially hectic gameplay.
You'll be able to walk freely around the map, either shooting all manner of enemies directly, or shooting explosive canisters, causing large blasts that take out (or at least highly damage) anything in the surrounding area. Each kill earns you experience points and an element called "Xplodium," which is converted into coins after each level. As you level up, your Gun Bros will become stronger, receiving health boosts, and you'll also be able to unlock new items in the store.
For each wave, there will only be a certain number of enemies to defeat on the map. You might have to walk around the entire map to find them, though, as their spawn locations appear to be random. You'll earn more coins the longer you stay alive, via the Xplodium multiplier. Again, Xplodium is converted to coins, so you want as much as you can get. You can increase your rate of coin production even further at the actual Xplodium conversion screen, as you can either trade all Xplodium for the mineral's exact value in coins, or you can purchase better conversion pods, giving you, say, 120% of 150% in coins.
Items in the store include health refills, new guns, armor and power-ups (shields, instant damage items, etc.). Guns have damage ratings, while different pieces of armor (helmets, pants, vests and so on), each come with different defense stats, and can also have an affect on your attack and speed stats, either raising or lowering them. It's in finding the right balance of different stats that you'll have the best chance of surviving. Unfortunately, however, there seems to be a heavy reliance on Facebook Credits as a premium currency, as many of the most worthwhile armor items and guns cost real-world money to purchase.
In terms of social features, you can track your progress against your friends via the provided leaderboard, which shows off your overall level, and which wave you've reached in which particular Revolution. As of right now, there doesn't appear to be many other ways to interact with friends, other than simply inviting them to play the game altogether, but it will be interesting to see if a sort of co-op mode is added in the future, replacing the AI controlled Bros on screen with a real friend, or at least giving you a boost if you partner is represented by a real friend.
All told, the game's high production values show that Glu is serious about making Gun Bros. a success not only on iOS, but on Facebook as well. If you'd like to help them out, give this one a shot.
Play Gun Bros on Facebook -->
Have you played Gun Bros on iOS? How do you think this version of the game compares? Let us know in the comments.