BM2 - Subspace Bitmap File is a file extension that can be used to play different games. If you are using Subspace, then you can make note of this extension. It is a shooting game which requires an extension for added features. You can use this extension to add images and much more. Everything is stored in bitmap format as well. There is also additional security you can take advantage of when using this extension. There is also cheat prevention you will be able to take advantage of when you download this extension for playing this game online.