We have received numerous player reports about the game not launching from Steam and found that some users may experience this issue due to conflicts with the lsass.exe service, which is a security feature of Windows. We are investigating this issue and will release a fix for it as quickly as possible.
In the meantime, in order to launch the game, please start it from Steam repeatedly, it should successfully launch in up to 3-4 attempts.
If you are facing further issues with launching the game after a few attempts, please do not hesitate to contact us via this link: https://support.madfingergames.com/hc/en-us/requests/new