The game is currently being evaluated by a publisher. The publisher has called attention to a few areas that they feel could be improved, so I've been brainstorming possible solutions.
First, the publisher feels the challenges are insufficiently tense. We could switch from the current "pay cards to resolve" system to a "press your luck" system. When you face an encounter, you need a certain number of 'successes' to get a reward (some rewards have a few tiers or "stop points"), where a success means "you drew a white cube out of a cup containing white and black cubes" -- correspondingly, "failure" means "you drew a black cube".
Before you start drawing, you have to add cubes to the cup, of course. You add one black cube automatically, plus one for each Enemy Operative in the city. Then you can pay adventure points to add white cubes. However, the catch is that you don't get "extra" white cubes back even if you pass the challenge -- whatever you committed to the cup is lost.
This is part of an overall simplification of the outside-the-temple system, which used to have Enemy Operatives, Ally Cards, Item Cards, Reward Tiles, Theme Cards, and probably a few other things. It wasn't unmanageable, but game length is a concern of the publisher's so streamlining will give the players less to do, which should make things quicker.
Second, the publisher wasn't happy with the temple; they felt that it wasn't tense enough. Specifically, they would like something more interesting with the temple challenges. The new idea changes the way the temple is navigated and the info about the temple that the game "knows".
To move through the temple, you'd now pull a cube from the cup for each move. White means "safe move", black means "you hit a wall", which physically gets added to the board. Brown means "you triggered a trap!": draw a trap tile, place it on the room and resolve. Some of the traps could have special effects, like the boulder that continues to roll through all rooms in a row until it hits a wall, or poison gas that affects all adjacent rooms. Resolving a trap, though, will be quick -- just pay a card in that challenge category, or else...not sure what, get sent back to the entrance, I guess.
So the topography of the temple -- its obstacles and routes -- will be assembled on the fly. The location of important features in the temple, however, would now be contained on solution cards. The cards will no longer know "the grail is revealed by pulling the Lever" and it's that you have to find the Lever; rather, it knows that the grail is in room D3, and you have to use the clues to navigate the temple to find that the grail room is D3.
Finally, though not directly in response to the publisher, I also had the thought that instead of giving clues in order, it could simply be that each card has 3 or 4 available clues and you can access any one you like. I'm not sure if they're all equally good or perhaps some are slightly better (maybe it's known which is which and the better ones cost more?) I like this idea because I think it will create more asymmetry between the players. If there are 12 total clues in each game and a player typically accesses, maybe, 7 or 8 of those, then you know a lot but not everything, and what you know is different from the 7 or 8 things that other players know (although there's some overlap). If Joe goes east in the temple when you went west, is it because he knows something you don't know, or are you equally clueless?
There are two other ideas that I don't think are as game-changing but that I still think are worth trying.
The first is quite simple: players can use Adventure cards twice. The first time, you play from the hand to the table; second time you discard. I think may make intermediate-range planning a little easier on you. And, it might give you tougher decisions about possibly using a card "inefficiently"; you know you'll get to use the card again so maybe you're tempted to use it just for an AP instead of holding out for a challenge in its category.
The second is to allow player trades through a simple card-based mechanism. Open negotiation is a time sink, but structured trades could work. There would be three "trade cards", each of which shows two rewards, one on either end of the card. To initiate a trade, you simply place the card between you and another player, with the reward that you want to get facing you. The other player can accept, or counter by replacing the card with one of the others. The trades would be to swap check marks (which represent information) or for adventure cards, mostly.