There's a new possible cause for the game just blacking out, or doesn't continue past skipping the prologue. The game uses localStorage, so if this is full for NewGrounds or uploads.ungrounded.net, the game will not work properly. The error is silent and will cause the game to not continue playing by just showing you a black screen. This can be solved by:
1.) Clearing your browser's cache (this is overkill, but will do the trick for most)
2.) Removing site-specific cache data. This is usually found in [Cookies and Site Data] settings in Firefox. In Chrome, I think this is tied with cookies. You can look here:
Settings -> Privacy and Security -> Content Settings -> Cookies -> See all cookies and site data -> Look for newgrounds related sites where there's localstorage being used (ex: uploads.ungrounded.net) and press the trash or X icon to clear them up.
In the next update, I've added a message that tells you if your localStorage is full rather than just blacking out.
Thanks to @BobUncle for letting us know about this!