Matrix/Slitherine customers will not have access to the Battlefront version and vice versa. Customers who buy from Battlefront will have access to the Battlefront version and Steam key. Customers who buy from Matrix/Slitherine will have access to the Matrix installer and a Steam key.
Multiplayer is possible between versions. Steam requires all the game content to be in the install folder so the placement of some files will be different to the Battlefront version but this is all behind the scenes and the features are identical. The versions on Matrix, Battlefront and Steam are identical apart from some minor changes to make the game compatible with Steam.When purchasing a bundle on Matrix/Slitherine you will receive a serial for each part separately.Each will generate a unique Steam key for that piece of content on Steam and must be redeemed on Steam separately. if you purchased the base game and British Forces bundle you would register that serial twice, once to the base game and once to the DLC. To redeem all the pieces of your bundle as Steam keys you will need to register that serial for each part of the bundle. Note that if you bought a bundle from Battlefront you will only have one serial for all the games in the bundle.
We wanted to give you some details on how things will work and both teams will do their best to make this process as painless as possible for you all to get your games working on Steam. We’re very pleased to be working with Battlefront and know many of you are eagerly anticipating the release of Combat Mission. Here are the instructions from Matrix/Slitherine on how to get your Steam key: