Okay. If it is, you can still launch the game by clicking "More Info" label then check the "I understand the risk and want to run this app" and finally click "Run Anymay" button. (Text on label/button might be a little different because I've translated it)
I'm sorry for the inconvenience, the message indicate that the game was downloaded from unidentified source/unrecognized app/unknown publisher, which I am.