Downloading StarBreak 1.12.1 for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available. This free Mac app is a product of Crunchy Games. We recommend checking the downloaded files with any free antivirus. StarBreak for Mac lies within Games, more precisely Action.
From the developer:
StarBreak is a co-operative action combat platformer MMO with perma-death and procedural generated content. Playing the game, you will explore strange sci-fi worlds alongside dozens of other players, kill legions of dangerous aliens, and fight epic boss battles.
You may want to check out more software for Mac, such as Jets'n'Guns, Kivi's Underworld or Passage, which might be similar to StarBreak.