Hi! Apparently I have the same problem as you and for the other games that have exe file. So please, if you find the solution, please tell me here. I saw a comment of someone who had the same problem as us and sakevisual said we should open realistair.app which have a big purple icon, but I can't find it. :/ Thank you!!
What I did is I found the file that had the game icon and right clicked to view the package contents then went into Mac Os foulder and then clicked on the code looking icon and the game started playing