Does the game provide any kind of error message? If so, can you share it with us? Otherwise, please check you've downloaded the MacOS version, that it's downloaded to the desktop and not a cloud-sync location, and... sometimes just restarting the computer can fix things.
If you've tried all that and it's still crashing, you might need a small bit of additional software to run the game. Don't worry, it's free and safe. Here's what to do:
1). Download the game file and extract the folder (Grove_0.204) to the desktop.
2). Download the normal version of NW.js (https://nwjs.io/) and transfer the app to Applications.
3). Go finder, utilities, terminal and use the following command to launch the game: open -n -a nwjs --args "/Users/name/Desktop/Grove_0.204"
(the "name" should be your username for the file path)
Hopefully one of these solutions should work for you!