It stucks in an error loop:
Uncaught TypeError: Cannot read property 'apply' of undefined
Press F12 if you use FF or Chrome before you hit start and chose the tab console and you will see it.
If you you use a beta version of C3 try the stable version, if you minifying your game try without it.
Or make a bug report: github.com/Scirra/Construct-3-bugs/issues