That is one of the toughest questions I've been asked...since the game is really not that easily defined, but rather than answer it in the Comments section of that journal entry, I've decided to offer my thoughts on the game here.
Fvlminata: Armed with Lightning is a roleplaying game that is different than most of the Roman RPGs that have followed it. The game is set against the backdrop of the mighty Roman Empire, and is for the most part a historical roleplaying game. However, the game is definitely considered alternate historical because, as the name of the game implies, Fvlminata postulates an alternate reality of the Roman Empire, where Auifidius Caelus discovered the secrets of gunpowder [fvlminata] in AD 96, and changed the shape of the Roman Empire forever. Furthermore, the world of Fvlminata behaves according to the ancient worldview, which allows the characters to inhabit a world of mystic secrets, spirits, and potent magics (but all from the Roman view of the times). One can definitely run the game without the gunpowder elements and the magical elements, and use the readily available historical timelines of the Roman Empire to do a significantly more historical game, or one can run the game in the default setting or anywhere in between.
That said, unlike many of the Roman RPGs that have been published in recent years that have been influenced by movies such as Gladiator and the like, where fighting and combat in the Roman military or gladiatorial arenas are the focus of the game (and yes, that was a generic statement), Fvlminata focuses on the social nature of Roman society, and on being *Roman*. This is a game about political and social intrigue and daily life, rather than combat and arena battles, but future supplements for the game promised more of those elements. In order to accomplish this, the game Attributes are focused on the Roman ideals and notions, and the four Humours that defined Roman behaviour and temperament are also part of the game. The game uses four stats - Intelligentia, Agilitas, Pietas, and Vis - and divides its Skill up by Gods. Horse Riding, for example, is covered under Poseidon, while Charioteering is covered under Ivppiter. Lovely stuff. In addition, the game also includes the four Humours - Melancholius, Sanguinicus, Flegmaticus, and Cholericus - that so defined Roman behaviour and temperament. What this means is that one plays totally normal people in this game, not adventurers - actors and augurs, farmers and felons, politicians and prostitutes, sentries and slaves.
The game mechanics are handled using four Tali dice, and are quite neat, as they emphasize the different types of Tali hands - Senio, One Pair, Two Pair, Three of a Kind, Venus, or Vultures - but some may be turned off by the mechanics of the game. I won't go into mechanics here any longer, but suffice it to say to each their own. The game mechanics are pretty light, and that may not appeal to folks, but the strength of these rules is that they don't get in the way of playing this game, and being Roman.
The book also has some of the best coverage of the Roman Empire, in terms of its cultures and other subject matter, seen in an rpg to this point. A marvellous, relatively short chapter deals with geography in ever increasing circles. First we see the layout of houses and temples, then the layout of Rome itself, then the layout of the entire Empire, and each little bit of each one described and delineated along the way. This is followed up by a chapter on the history, government, and law and order in Rome. Then there is the massive chapter on sociology, culture and daily life in Rome. This covers *everything*: dress, fashions, customs, births, deaths, marriages, families, jobs, food, wine, religion, festivals, money, industry, trade, science and medicine. Great stuff. The next section deals with Ludi, "games of life and death". Gladiators, chariots, and ravenous wild animals, and best of all, some rules to go with them. This is followed by a section on War. You get information on basic tactics, army formation, structure and management, the life of a legionary, cavalryman and naval officer. Details on a whole bunch of other groups, from nightwatchmen to the elite guards. Heck, even the names of forces and where they are stationed are included.
The material presented on gunpowder and magic is somewhat...lacking, though I found it to be adequate, and with 60 spells provided and some good mentions of other types of magic available in the world, there is some meat for the GM here. The real problem with this material on gunpowder and magic is that when one veers away from the historical elements of the setting, the veritas of the game suffers somewhat. Still, the magic rules are quite nice, quite simple, but somewhat vague overall.
For those interested, there are several reviews of the game over on RPG.net that offer all sorts of overviews and opinions about the game. If folks would like to see a sample of character generation, that can be arranged too. Just ask me about this in the Comments. :)