No idea it wont let me play it :( It looks so fun
For Windows(Sorry if you're an IOs user):
When it shows that "Windows is protecting you" There will be a 'More' button. Click on it and click 'run anyway'. It is safe but Windows shows this thing when a program is from an unrecognised author.
Edit: Whatever I said doesn't mean every itch.io games are safe I referred 'It' as 'this' game.