I'm sorry you can't open it! Have you tried double clicking on the .dmg file? It should open the file you need to drag into the Applications folder. I don't have a mac I can test it on rn so let me know if it works!
Actually, are you trying to open it through the itch app? Could you download the game on your computer and try those steps there?
I was trying it through itch! I did the steps on my computer directly and it worked, thank you! Excited to play! <3
