I'm playing through all the Mansions of Madness scenarios I own, and reviewing each one as I go. The first one is Cycle of Eternity, which is one of the introductory adventure included in the main game. My short spoiler-free review is that Cycle of Eternity is a combat-heavy and very challenging scenario with a nice and simple plot. It's much more difficult than its difficulty rating suggests, however, so I don't recommend playing this first. For the rest of this review, there are minor plot spoilers, so don't read on if you want everything to be a surprise.
I think Cycle of Eternity is likely one of the first experiences most people have with Mansions of Madness, and that's a real pity because it's horrendously misrepresented by the app. The publisher gives this scenario the lowest difficulty of all scenarios from the box (and the 3 expansions I currently own), with a rating of 2. In reality, the scenario has several very difficult combat encounters, a huge map, a challenging final battle, and a race to get out of the mansion with the required evidence. It's exciting but it's not the least difficult scenario in the box by any stretch of the imagination.
There's not much that's bad in Cycle of Eternity, aside from it being a poor introduction to the game but being positioned as an introductory adventure. However, I've played the scenario at least 4 times, so it's one of the scenarios I am most familiar with and therefore I've got a small list of minor annoyances:
Even at a higher difficulty rating, I wouldn't love these 4 aspects of the scenario. I don't consider starving the players of resources and then intentionally ambushing players with a monster a fun challenge, and I don't understand the intention with the elusive butler.
The misleading title is forgivable. A cool sounding phrase is a cool sounding phrase, after all. But as a Lovecraft reader, I found it jarring that a phrase extracted from one of Lovecraft's most famous stories was used in a scenario dealing with an entirely different aspect of lore.
Ignoring the errant difficulty rating and my minor complaints about the writing, this is a really fun gauntlet scenario. Even after you determine what's happened to Mr. Vanderbilt, you can't get into the room you need because you don't have the key, so a secoundary investigation begins. And there are yet further story threads you can follow. There's a lot of content in this scenario, and it all tells a properly gruesome Lovecraft-style tale.
And that's not all. Having played this scenario 4 times, I was pleased to find that the map wasn't entirely pre-determined. In the game I played on my Youtube channel, I followed the butler's instructions to look in "the Office", found a Study and investigated it by mistake (it didn't occur to me that a home Office was different from a Study). Once that got resolved, I found Vanderbilt in the Attic instead of the Garden where he'd been during every other playthrough. It kept me on my toes.
I'm generally a fan of replaying games, and with Mansions of Madness I enjoy the variables introduced by playing with a different set of Investigators. But when you add to that a change in the map and a variety of monsters, the scenario gains a lot of added value. I guess I probably paid $180 NZD for Mansions of Madness, and from the first scenario alone I've gotten at least 8 hours of play (and that's charitably assuming each playthrough only lasted 2 hours).