How can I play against my friend ?
There are two versions of Real Boxing on PC:
Steam and boxed version.
Real Boxing on Steam offers both the internet and local multiplayer modes. To start the mutliplayer game over the internet you need to have a stable network connection and then go into the Multiplayer mode and click on Fight.
The boxed version provides only local multiplayer mode for you and your friend to fight against each other in the comfort of your own home. For local multiplayer just plug in two game controllers (or one if you prefer to play using keyboard) go to Quick Fight, choose a fighter and click on Fight Button.