This is a personal, largely spoiler free (or spoiler-vague) review of the Of Sphinx and Sands fan made campaign by M M (Mat628) for Arkham Horror the Card Game.
In Of Sphinx and Sands, investigators are called by Dr. Francis Morgan to steal an artifact from a local museum and run to Cairo, all while dodging the machinations of a mysterious cult. The campaign is meant to be played with characters between 8-12 starting XP, and can be fit within another campaign.
The primary feeling from Of Sphinx and Sands is that it is very confused as to what it's trying to do and what it wants to be. There are a number of optional modifications for scenarios, including right in set-up, with no indication of why you should or should not use them - it's as if the design is unsure of itself. The mechanics don't feel much better in play - each scenario ends up having significant set-up text, requiring you to break up encounter sets and set them aside, adding individual cards to the encounter deck as you go, ruining the entire point of having distinct encounter sets. You're fiddling with the locations and encounter deck so much, it ends up really slowing things down. Further, the barebones story attempts to integrate with existing Arkham Horror games, like including Francis Morgan - and yet features transatlantic flights on private jets, modern graffiti art featuring respirators, and says Cairo has a population over 10x what it did in the 1930s, and even bigger than what it's at today. There's no sense of cohesion or adherence to basic history, and it ends up being extremely distracting.
Of the three scenarios, the first plays best - it's a museum heist, with cultists only entering after some turned have passed, and with an issue of dealing with security guards. The mechanics are strange here though, suddenly asking you to remember how you dealt with some enemies which it didn't ask you to note at the time. There's also a mechanic of random civilians in the first agenda you can deal with for clues - but they require actions to reveal, and are around for such a short period of time you don't really have a chance to use them if you have any sort of assets to play at all.
The second scenario is a fairly standard clue getting one that constantly expands the map, removing all clues from previous locations as you go, and continuing to expand the encounter deck. One of the optional (but recommended) modules here basically introduces a mechanic very similiar to The Scarlet Key's concealed - but it only allows basic investigates, posing a problem for a lot of investigator parties. The last bit of the scenario also has the problem that it brings out Hunting Shadows, which asks you to give up clues or take damage, in a scenario that simply demands you get a set number of clues to advance - and not a "do all you can" situation, where Hunting Shadows belongs. The entire scenario also feels too long, and too large.
The third scenario is by far the worst. A variety of new rules are introduced in the campaign log that will constantly need to be referred to, and they just end up bogging down play. Constant willpower checks are needed to move from one location to the next, with clues allowing you to pass them more easily - but you lose the clues once you move, and you can be forced backwards. It's an exercise in frustration with far too much to track, and too much mental load for what's not interesting to play out at all.
Overall, Of Sphinx and Sands isn't worth the time - it's a messy campaign that motions at what might be good ideas, but doesn't develop any of them enough to enjoy.