If I had to sum up AoS in two words they would be: Superhero Fantasy. The heroes start as a very competent, assembled by the Gods, team forged together by a bond. That bond gives them access to some shared powers over above what they get when they pick their archetype. Every characters has some cool guy stuff they can do.
The Mortal Realms are an extrapolation of of the old WHFRP Winds of Magic, each of the 8 Winds got a Realm associated with. It sets the basic conditions for the realm to Aqshy, the realm of fire, is hot, filled with deserts, ash wastes, and has problems with Khorne.
The team, the Soulbound characters, oppose the machinations of the Chaos generally. There are over 20 archetypes in the core rulebook alone and each expansion adds more. Champions of Order is generally considered an auto purchase addition to the game. It contains more than 60+ archetypes that round out what is available to play in the RPG with what is available to play on the tabletop. There are a wide variety of archetypes, three factions of elves, two factions of dwarves, Stormcast Eternals and their various subfactions, Sylvanteth, and so on.
There is plenty or Lore scattered throughout the book. C7/GW really want you to be able to imagine the world your playing in. There are about a hundred pages of just lore about the Mortal Realms, Factions and Religion. Every Archetype has some lore in its entry and so on.
The book is a standard two column format with a legible font size (my eyes aren't what they used to be). The graphic design is satisfyingly easy to deal with. The art is fantastic, as expected, when you have access to GW's artists and product.
The Starter Set is an excellent entry point, much like the WHFRP 4e starter set it comes with an adventure or short series of adventures and a fleshed out 64 page setting guide to the city of Brightspear. The city book is well done with plot hooks and with enough meat to run it for a while. It also comes with pre-generated characters.
It's action packed almost superhero fantasy gaming in a fantastically wild setting with lots of opportunity to do your own thing but enough baked in support that you don't have to.
There are Talents (read feats) they can modify or change a bunch things and are mostly silo'd to a given archetype.
Advancement is an experience point buy where Attributes, Skills and Talents can all be purchased. XP is supposed to be given for Short and Long term goal completion, both characters and the party as a whole have both.
There is a meta-currency generated by the Soulbinding ritual called Soulfire which can be used for a variety of different things from re-rolls to cheating death.
Mechanically it's a attribute + skill d6 dice pool. Skills are measured as Untrained, Trained ranks, and whether they have a Focus. The dice pool is built from Attribute + Trained Ranks. If a character has a Focus in a skill they can add +1 to a given die result. Difficulty Number is comprised of two parts, the Difficulty of the Test, and Complexity. Difficulty of the Test is what face you need on a given die to count as a success. The Complexity is the number of successes needed. The Difficulty Number is expressed as DN X:Y where X is the Difficulty of the Test and Y is the Complexity. DN 3:3 means every three is a success and you need three total success to pass.
Zone based combat system. Target numbers in combat are determined by comparing your combat stats vs. the opponents. Single success required with additional success overcoming armor and adding to damage. There are optional rules for opposed rules if you want them. Characters have a Toughness pool, once depleted damage is converted to Wounds on the Wound Track. Toughness pool can be refreshed with a ten minute rest. Eight hour rest will clear one wound on the wound track.
There is a Downtime system included in the Core Rulebook and expanded in the supplements.
Bestiary included with the book, and of course expanded on through supplements. Plenty to get started with. There some stuff in the GM section about making the game feel like your playing AoS and not just another generic fantasy game. They want this game to tell EPIC stories. For mud and blood see WHFRP 4e.
The artwork and cartography are fantastic. The game has numerous expansions and adventures, including at least one three part adventure series (path). The license was just renewed for I think, another 5 years, across the board for WHFRP, AoS, IM, and W&G.
I have not gotten it to the table yet but really, really, want to. My SW Night's Black Agents game will take a break in about 6 weeks. When it does I may run a short AoS campaign before we go back to it.
And yeah, the IP thing was a real issue with AoS launched. GW could not copyright Elves or Dwarves or Ghosts but Aelves, Duardin and Nighthaunts? You be they could That said there's a ton of lore expansion for this setting from the tabletop game and the rpg, and cross proliferation between the two as well. The lore is interesting and evolving. The world setting is 8 years old at this point and has seen continual growth every year on the wargame side. A ton of the wargame campaign material could definitely be used to fuel stories in the rpg.
One more last note. The game is VTT supported through C7 on Foundry with an official Foundry Module and add-ons for supplements and adventures. If you bring it to the table you can definitely always find the perfect miniature.
