We had problems where we'd reach a door card and neither of us had any cards we could play. Both of us picked heroes that we couldn't use an ability to discard cards. What do we do? I don't see any rules about just straight discarding cards.
The rules state this as one of the losing conditions.
The skull door cards. Do you take them out of the deck before shuffling the door cards? Meaning for a 2 player game there will always be a maximum of 4 mini bosses? Or are you supposed to keep all the other ones in the deck before shuffling?
The 'skull door cards' are called 'challenge cards'. There's a table on the backside of each boss card stating how many door cards and how many challenge cards you use. And that means you have to separate them after each round.
Speaking of shuffling, is it me or is there a lot of after-round shuffling and sorting because all the cards get mixed up?
With a two player game are you supposed to shuffle say all the Red and Yellow cards together, or are you supposed to put the Red deck "on top" of the yellow deck, meaning all Reds get played first?
No. You shuffle both decks together. Each deck contains a resource type that is more common than the rest. If you shuffle both decks together, you make sure that two resource types are more common.
When discarding, you should place your cards face down or face up? Being able for everyone to see what your top card is seems to be advantageous.
Face up. (see the special ability rules section)
We've only played a few rounds but it seems like you may be able to get in a feedback loop of healing and powerful action cards which would greatly reduce the difficulty of the game?
Action cards you use are not discarded to your discard pile. You play them to the center of the table just like resource cards.
Finally, and again I'm only a few rounds into it, but I genuinely can't imagine getting to and beating even the 3rd boss in 5 minutes. We're barely able to do Boss #2 with about 15 seconds left. We always seem to get more hung up on the collection and discarding of the physical cards over the game play itself, are there any strategies about speeding up the actual card handling without throwing them all over the room?
Determine one player to flip the door cards over and another one to sweep away and pile up the cards used to defeat the monster/challenge.
Also: Don't be afraid to lose cards! F.e. if two or more players play the same resource card simultaneously, don't discuss who loses the card. It's better to lose both cards and keep on going.
Try to pick at least one character who has the ability to let other players draw cards and make full use of the special abilities.
If you've never run out of cards, you're to hesitant with your special abilities.
The 'Stop Time' ability of the Wizard f.e. allows your team to pause the timer, to clean the table up a bit, to discuss who defeats the current monster and how, what special cards to be used - or maybe even more importantly - to discard three cards just to draw new ones.