The single biggest change during playtesting has been the Activation cards. During SSO each player is given a number of movement cards depending on their number of crew which they then play face down next to their crew cards before revealing and following their instructions. The effects of which are three fold; one and most basically, player options are based on chance whilst being controlled enough to not be random. Two, it means players can conceal their intentions from others until its too late so that if they are opting for non-co-op play they can mislead and betray their friends. Three and most importantly, it means players must have active conversations to coordinate their actions and achieve their aims. All of which was basically fine in itself as these things go, but once the crew were in the location of greatest use and the current set of missions complete the Movement phase could become rather null, which led to the aforementioned major change. Simply, most, but not all of the movement cards had secondary effects added varying from extra Morale for higher ranked crew to shifting extra Challenge cards. The effect being that it is constantly of value to move around the ship in an intelligent, coordinated fashion, it saves a phase from falling to null choices. The hand off was that the game became more interesting but instantly a degree easier. Now, I fixed that by simply making the effects of Challenge cards a notch more punishing, raising an interesting point on difficulty verses fun.
Difficulty and fun is a tough design balancing act. If a game is too tough or too easy its no fun. Also its easier to write a crushingly difficult game than a too easy one, especially for a co-op where its easy to see the game as designer vs gamer. You can put in some difficulty variations, but fundamentally players have to win after roughly 3-6 tries on intro mode to want to move on to harder modes anyway. Its surprising how players will work to beat a game given a relatively small impetus of fun, so a notch more difficult is usually safe provided you pay your player back with fun. To explain, by fun I mean usually two things; one, discovery and two, active choices. Discovery can be tough in a table top games set up, which is why legacy and expansion elements are so popular, but hopefully if well written the game will lead to layers of discovery via emergent game play tactics (of which more in another blog). Active choices are the element I most often consider to fulfill the "fun" category, clear divergent choices with risk reward weightings to pick between with the correct choice resulting in relativity satisfying rewards.
So that's my basic conclusion on that matter, there is a sweet spot of difficulty. That bullseye, however can be broadened by offering the player additional interesting choices. When I alter or add a feature that may raise or lower the difficulty my first criteria for its inclusion is "does it force the player to make an additional choice?". Usually the second criteria is "is the additional choice just irritating?". Happily I've had to throw out relatively little on the second question.