Presentation is excellent. World vs. Hero (WvH) is written clearly and concisely, the examples are lengthy and illustrative. The artwork is a notch above the indy press norm -- not perfect art, but the author (John Fiore) cleverly writes examples so that they match up with the artwork, making the best with what's available. Word Mill Games did a good job with the PDF production, and Fiore also gets kudos for being an active member in the community, and in actively continuing WvH development on his web site.
Without giving away everything, after world & hero creation, the World player generates a certain number of encounters in advance: A deck of playing cards then determines what encounters the World player can use to challenge the Hero player and the intensity of the challenge (in a storytelling fashion); the cards in turn determine how the Hero player can respond (using generally conviction/wisdom, intelligence/magic, agility or fighting prowess) to the World player's challenges, and the intensity of the response. There's more to it, but that's really the core mechanic, and most of the game.
Perhaps I was expecting more Mythic RPG-like elements, or a higher level of evolution based on the high-quality storytelling games already out there. I think the WvH card-based storytelling gameplay mechanic is overly simple: The World player describes what happens based on an encounter, the Hero player describes the response. The only random element are the cards available to be played (determining which encounters the World player can choose to draw upon, and that the Hero player can choose to respond). If one player doesn't like the narration of the other, they can veto: with the stage of the game (early, middle or late) is a factor in which player should prevail in a narration challenge.
Here's what I think would WvH needs:
(1) Integration with Mythic RPG's GM Emulator as part of the basic game for solo play. The author is working this out on his site, it would've been a nice element in the basic product. Alongside solo play/Mythic integration should be variant gameplay that lets the World player generate encounter challenges randomly that the World player can run with, to make it more of a 2-player pickup game.
(2) Some sort of randomizer that throws occasional curve balls at each player in turn, the same way Mythic generates Altered Scenes, Interrupts and random events. Keep everyone on their storytelling toes.
(3) A conflict resolution system that lets players challenge each others' story elements in creative ways. A bidding system that lets players bid to take control of (e.g., randomly introduced) story elements. Possibly a subsystem to determine the outcomes of possible conflicts (instead of narrating what happens, somehow dice out the challenge).
(4) Some sort of tracked metrics throughout the game that let one player or another make sacrifices and cede topics, and then use this "karma" for greater leverage at some other point in the game.
I think the game is nicely presented and it's definitely playable. I'm a harsh critic because I keep an eye on The Forge (Indie RPGs) on and off, and already own some powerful storytelling games -- Ben Lehman's brilliant Polaris, Seth Ben-Ezra's Dirty Secrets, and of course Tom Pigeon's Mythic RPG. These are just plain stronger products than WvH is in its present form. I don't see myself using this game as it is, I think it needs lots more structure and more mechanics -- ie., levers for each player to pull in their struggle -- than the core mechanic currently offers. Hence two stars -- it's not outright bad, but I had higher expectations and do feel let down.