Andy Phillips is of course no stranger to the IF world; before this game he had previously come out with Time: All Things Come to an End, Heist, and Enemies (four large games is enough to make him noteworthy if only for sheer quantity). Heroine's Mantle carries out almost every trend raised by his previous games (except, thankfully, the grammatical errors, which are toned down considerably) and molds them together into a game that, for the first time for Phillips, feels complete and well-structured, and carries its story with confidence.
Here is what happens in the first twenty points or so of Heroine's Mantle: you are saved from drowning by a superheroine, you grow up, you sneak into an office building, you attend a party, you find out the world is threatened by a master criminal, you have an encounter with a female assassin, you force your way to the penthouse, you re-encounter the assassin in the middle of one of her nefarious schemes, you battle some elite bodyguards, you hack a computer, you ransack an office. Point-wise, this has all happened in just the first five percent of the game. Later in the game, you battle various super-villains (including a space-pirate), fight untold number of robots and secret cultists, save the city from being poisoned, save the mayor from being assassinated, and this is all in the same game. Nobody else has done this, or really anything close.
To make this massive storyline go requires the player to make mental leap after mental leap, often blindly, hoping the game will be there when you land. There are machines that have to be fiddled with for no other reason than that they're there, capabilities of your ship that have to be guessed at because they're not fully explained anywhere, even actions that have to be taken for no apparent reason other than that, in retrospect, they look good. And people hate this.
I obviously can't tell people not to hate that in a game, but I can say that you should be understanding this as a baseline axiom, not as a flaw. Meyer Schapiro has this thing about the importance of a the frame in doing criticism of a painting: it tells you where to stop looking (and, thus, where to start). Galatea is set in a single room, with a single NPC, with no takeable items. This is not a failure of the game or a problem with the design. It's the frame of the painting that tells you "this is what I'm interested in; this is what to focus on". All IF has restrictions: from the parser, from the world model, from our inability to code NPCs that can hold "real" conversation. And the best games take these restrictions and deal with them, whether it's Galatea with the tiny world that focuses you on the single NPC, Spider & Web with the restricted conversation options that lead to a tense and weighty dialogue, or Heroine's Mantle with the forced actions and crazy puzzles that let Phillips create a huge and glorious storyline.
I should perhaps say a few more words about the superhero genre that the game belongs to. Up til now, there was a distinct lack of superhero games in IF. Some good ones have been written: Hero, Inc and the two Frenetic Five games, for instance, but the most successful have all been comedies. Some part of the superhero concept is indeed comedic, but mostly it isn't, and we've been waiting for a game that could capture the whole spirit of the superhero genre. Heroine's Mantle succeeds. It has humorous, even silly, bits: wacky villains with strange motivations, ridiculous traps, and goofy innocent citizens who talk to and/or hinder you. But it also captures the larger-than-life, super-good against super-evil, fate-of-the-world-depends-on-this feeling that is so necessary for realizing the promise of the genre. Most games have failed because they're too timid; Phillips dares to go farther and drags the player along with him, willingly or not. Even the puzzles add to the feeling of the titanic struggle — there I am, 2am, grappling with the game, a few cryptic hints, two megabytes of txd output, and I'm still stuck. Meanwhile, the PC is engaged in a duel to the death with the space pirate on the bridge of the submarine while trying to figure out how the hell she can also divert the torpedoes from an ocean liner full of innocent lives. You want "complicity"? It's all here.
For certain sorts of games, the best reaction you can have as a player is "I want to do something like that!" Heroine's Mantle is doing so many new and crazy things in so many areas that there are dozens of possibilities that fly out in all directions. And what I'd most like to see is for lots and lots of players to grab a walkthrough or txd (or nothing at all besides the .z8, depending on how much patience they have), play this, and then go out and write some games of their own.