Here it is then, the full game: https://www.drivethrurpg.com/product/397654/Mysterium-Weird-Fiction-Roleplaying
The major change from the previous beta version is that there are four new scenarios (for a total of six) with rules for different weird and paranormal phenomena, powers and beings.
The Door to the Unknown An entrance appears in the PCs home, an opening to a place beyond the world, a place that is inhabited.
Lost and Found When reality warps, objects left behind can become imbued with strange properties and potentials.
Twilight Town They called into the abyss, and received an answer. Now their town is being dragged down into the pre-cosmic chaos.
The New Gods Seemingly divine entities offer power to reshape the world, but at what price?
Angel Tears This new drug gives you a “lucid high” where you can project into realms beyond that of ordinary waking consciousness.
Hidden Masters The PCs are thrown into an underground war where ultraterrestrial entities are fighting over the future of the human race.
The book is 150 pages long and available in pdf, softcover and hardcover.