You're going to need to give more details for us to be able to help you.
What version are you trying to play? Windows, MacOS or Linux? Have you downloaded the correct version for your computer's operating system?
You're not trying to play on mobile, are you? Have you made sure to fully extract the game files before playing? Have you made sure to save them locally and not in a cloudsync folder?
If the game is giving you an error message, tell us what it is.
Hopefully one of these suggestions can help you.