Are you seeing an Escaped_Chasm_Contents folder with Escaped Chasm and Extras folders in it? There should be an executable named "Game"/"Game.exe" in the Escaped Chasm folder and, if there isn't any, it might have gotten removed by an antivirus.
Do you run any antivirus programs and could you check whether they quarantined the Game.exe file? That's the usual problem behind files not appearing after being extracted from the archive.
I am also can't open the game.. any tips? I downloaded the game for the Mac and received the all the files. However, whenever I click onto the game file, my Mac says the file cannot be opened. I'm sorry if I'm bothering you.
I actually found a way to fix my problem. Instead of using the itch website to download the game, I downloaded their app. When I downloaded the game through the app, I was able to open it, but through the website, the game won't open. I'm sorry for the late reply.