Game won't start! Bouncing icon, then disappears

I downloaded Nancy Drew computer game and it wont start. I have dowloaded previous games and they all worked fine. Some games however will download onto my computer and then when I click to play them their icon will pop up in the dock for a brief second and then disappear. I have tried re-downloading the games. They still don't start. One game in particular is called Nancy Drew: Shadow at Water's Edge. I have even tried calling the HerInteractive company and was on the phone with them for 2 hours and they don't have any answers either. Help!

My computer is macOS Sierra version 10.12.6. Mac Pro. (Retina, 13-inch, Early 2015) Processor 2.9 GHz Intel Core i5. I have all my software updates. I am at a dead end.