I've been testing and tweaking the base game and first two decks for around 5 or 6 months now, and that was after some pretty carefully considered initial writing and a few months of massive overhaul. Which means for about 3 months the changes I've been making have been slight tweaks and future proofing against later expansions. But I just started testing the following four decks that might make it into the Kickstarter. The new decks are: "Parasite" representing an alien parasite infecting, replacing and killing the crew; "The Wonder of Wubs" representing a series of tiny fluffy aliens choking off the ship; "The Collective" where the crew splinter off into factions and mutiny against the Captain; "Temporal Anomaly" where a none specific phenomena is causing time shifts on the ship.
We tested "Parasites" which went well, very well actually, it bought up some of the most intricate choices thus far and bought the testers close to a couple of satisfying losses. So that's set for tweaks and adjustments, which is good. The "Temporal Anomaly" deck went not so well. The theory was that since every turn drains the ship's oxygen resources, forcing extra turns and repeating dealt with threats would be tense and interesting. The theory was wrong, the threat felt vague, victory unrewarding, and null turns depressingly regular. Which was a useful learning moment for a couple of reasons. One, as I've suggested previously my initial instinct with games is to take a rather dry and intellectual route, I'm amused by an active optimization problem to no end but I realise it's not everyone's idea of fun. Now I'm sure there's a version of that deck that I could find interesting a effective, its just that almost no-one else would. Two, the initial idea was that missions and cards would reset while oxygen would not and that the oxygen pressure would fill in for the lack of direction during mission free turns. Since the earliest version of the game missions were included but I had wondered how vital they actually were. The answer is apparently extremely, they lend the game direction and player impetus and no amount of pressure without them seems to recreate it. So "Temporal Anomaly" has undergone a total re-write in the mechanics, direction a