Prometheus was originally intended as a direct prequel to Alien, with the crashed Engineer ship at the end being the one found later by the crew of the Nostromo.

I think it would have been better to neatly tie it all off this way, but it seems now they have turn everything into a never-ending serial.

The original script for Prometheus had it as direct prequel to Alien.

The Engineer ship that crash landed at the end was to be the one found later by the crew of the Nostromo, with the dead Engineer in the chair being the Space Jockey.

It would have been better to have tied everything off completely that way instead of endless xenomorph and/or duplicitous android rehashes...