Never mind -- fixed! I forgot to navigate to that directory in terminal. Sorry about that! Disregard previous comment lol.
I've got my copy of the game on my desktop, inside a folder. I copy/pasted "chmod +x Secret\ Little\ Haven.app/Contents/MacOS/Secret\ Little\ Haven " into Terminal but am also getting "No such file or directory". Could you explain how I should modify the command to navigate to the correct directory in Terminal? Thanks for any help!
I ended up taking the game app out of the folder and adding "Desktop" after "chmod +x" in the command:
chmod +x Desktop/Secret\ Little\ Haven.app/Contents/MacOS/Secret\ Little\ Haven
I was then able to open the game via ctrl click->open :)