I give Mummy the Curse 4 stars: 5 stars for players, 3 stars for Storytellers. While Onyx Path seems to have succeeded in creating a game where the player gets an extremely powerful and effective character right from the start, the Storyteller section feels incomplete and does not give enough help for dealing with all the aspects of the game, especially the Powers That Be notionally controlling the mummies.
The Mummy as a character type seems created specifically to reflect modern gamers. Modern gamers, from my observation, have limited time, a (usually) thorough knowledge of their characters' powers, a strong desire to use those powers to the fullest extent possible, and a general drive to get as much good gaming done within that constrained time. Mummies start out with their power stat at maximum, a thorough knowledge of their own abilities and, for a limited time, no care for 'collateral damage', a hazy memory that makes a detailed backstory impossible (for the player) and remembering events of the last gaming session (potentially) unnecessary. They are driven by a purpose explicitly stated on their rising, and have a limited time in which to try and fulfil it.
Mummies have, right from the start, great supernatural and organisational power. Their supernatural abilities are divided into Affinities and Utterances. Affinities are 'always on' or activated by willpower, and are remarkably powerful for no cost. Utterance powers have three Tiers. The first is powerful, the third and often the second are full-on 'Old Testament Wrath of God', in power and style. They are described in a movie effects visual way as well. Mummy standard starting merits must include dots in Cult, and you can have a big organisation right from the start. Cult attributes are divided into 'legal' Reach and 'illegal' Grasp, and you can buy merits specifically for the Cult as well. The Cult system provides a method for resolving actions without the mummy by die roll, and for providing modern knowledge, services and general help when a mummy arises in a new decade or century. There is an interesting link between the mummy and his cultists in that several Affinities and Utterances make mortals more capable, sometimes permanently. Mummies also have a Tomb merit, rather more formidable than a Haven or Sanctum merit, and mummies and their powers are even stronger in their Tombs. Finally, while mummies are extremely hard to kill even temporarily, many of their Utterances can be used as death curses on their slayers.
The Storyteller's section, while featuring lots of potential antagonists and conflicts for mummies, seems to me to be lacking material integrating all the features of Mummy into a functional whole. The section on antagonists includes reasons for mummies fighting each other, the 'Lifeless', a varied category on beings created through necromancy, tomb raiders both individually and in groups, and a real surprise, an extensive section on ghosts with enough rules to make them player-characters. The chapter on the relics mummies so often pursue has a lot of detail, but relics are so unique I still would have liked a little more specific advice on designing them and their negative effects.
I didn't follow the development of Mummy, but when you read the Storytelling and 'Historical' chapters, it becomes pretty obvious that Onyx Path removed sections of the book without removing references to it in the rest of the book. The most obvious case is the total removal of the 'signature city', Washington D.C., to its own book. Sorcerers are mentioned throughout the book, without any explanation of how to portray them. The advertising for the game talked up the idea of keeping secrets to reveal to the players during play within the game books themselves. Those secrets have been kept from the Storyteller too, and unless they are in the upcoming Book of the Deceived, they won't be revealed. That brings up a general problem with the game: the Powers That Be that are supposed to control the lives of mummies are simply too distant, too out of contact with mummies and the living world to, in my opinion, be able to portray. You're supposed to convey the intricate machinations of the Judges and whatever else through ... when mummies are forced to make Descent rolls, and nothing else.
There is one last element that I want to give specific attention to: Onyx Path tried to make mummies symbolic of the oppressed, and failed. First, mummies are explicitly 'non-white' ethnicities. But that's only a problem if the mummy's cult can't appear rich. The book occasionally refers to mummies as 'workers', and in the Storytelling chapter it tries to claim that mummies identify with the 'underclass', those that work for distant masters. But the mummies were the slave-drivers of Irem, literally in the case of the Maa-Kep Guild. A mummy looking at a sweatshop isn't going to identify with the workers, but with the sweatshop manager. That mummies routinely abuse their cultists is described in the cult section and shown in the inter-chapter fiction. To top all that, mummies are immortals with the powers of demigods backed up by ancient cult conspiracies and notionally overseen by true gods so distant as to be irrelevant. Calling them oppressed is a very entitled view of oppression. Mummies are the oppressors. With their cults, they make better villain protagonists than even vampire elders ... a concept that is apparently dealt with in Guildhalls of the Deathless, which I don't (yet) have, but not at all in this book.
This corebook presents a game for dramatic, big-scale one-shot or limited campaigns. The elements to run a long term game have been removed, and I feel you need to either buy the supplements or do a lot of development yourself.
Suggested reading: the non-fiction book "The Mummy's Curse" by Roger Luckhurst. I found this in my local library. It is a general look at the evolution of Gothic fiction in the late 19th Century, and how it relates to the society of the time. Lots of interesting stuff for Mummy and for the World of Darkness.
[4 of 5 Stars!]