Hands on with the much anticipated real-time multiplayer update to Gun Bros.

It's hard to over-estimate how important topdown freemium shooter Gun Bros. has been for publisher Glu Mobile.

It's done over 10 million downloads on iOS and Android, and made Glu over $2 million last quarter.

But more significantly, it validated the company's focus on action free-to-play games in a genre previously dominated by casual time management FarmVille clones.

And that's why Gun Bros. is getting plenty of love when it comes to updates - the most important of which will add real-time multiplayer.

Of course, adding this feature to a game that already provides you with a buddy player is something of a no-brainer design-wise.

In this way, the only change to the game is that instead of having an artificial intelligence-controlled buddy, now you have the option to have a real bros. to fight alongside.

Still, this means you can be more tactical in terms of how you defeat the enemy waves, although because your buddy isn't limited to be in your screen space (as with the AI buddy), you have to be careful about where you both are on the map.

Thankfully, a buddy location arrow is provided, as well as real-time voice chat.

There have been additions to the gameplay too, the most significant of which is the revive option. This means that if your fellow bros. is killed in action, you can revive him by standing over this body - within the highlighted area - for a certain period of time, fighting off the attacking waves until he's up and gunning again.

Aside from the technical issues of getting lag-free action over wi-fi and 3G - it worked fine over wi-fi in our hands on sessions - adding multiplayer is part of a wider social refresh across Glu's titles.

Called the Glu Games Network (GGN), this cross-platform HTML5-based system will integrate with Facebook, Game Center, Twitter, MySpace and OpenFeint.

In terms of Gun Bros., this means you'll be able to better find your friends who have the game, sending them push notifications to get them to jump direct into a real-time game with you.

You can also play with random players who will be assigned by the network if you want a quick bout. This will automatically set up a game for a player with the lower character level to ensure a fun experience. Obviously, you'll be able to turn such ad hoc bros. into friends if you want to.

Linking into this will be what are called Halo Reach-inspired challenges. You'll be able to send these pre-set challenges to your friends, with each challenge met gaining the players GGN's currency - g points. Challenges will last for a 24-hour period, and initially be playable only in solo mode, although real-time multiplayer challenges will eventually be introduced.

A more subtle way of adding social elements to the game will come in the form of Bro Buffs. These will provide players with better in-game attributes the more friends they have.

Examples include a 10 percent increase in XP if you have three friends, or a 10 percent increase Xplodium yield (the game's soft currency) if you have five friends.

Adding friends is also encouraged as you're rewarded with Xplodium for sending out invites, as well as getting the game's hard currency - Warbonds - if/when your friends actually download and start playing.

The multiplayer update to Gun Bros., which will include new weapons and armour, is due in June for iOS (later for Android), while the Glu Games Network should be released sometime in the summer.