Lady Luck was not here today : first mission was a total failure, second one was a really thin win... Having a bad streak of events and obstacles can really slow down a game : "you lose cards!", "you lose money!", "you cannot buy!", "here is new hard obstacles to take the place of the normal wounded ones, you're welcome!", etc.
According to the box, an average game is 30-60 minutes, but it is often 75-90 when threre are 3 scenes : this can be a problem with some casual players or during busy gaming nights. To be fair, some players are taking too much time planning how they will play their cards and abilities, but I guess this cannot be avoided with some people...
I plan to write some missions in the near future and I'll try to insert an option for having 2 or 3 scenes (with proportionnal Karma rewards): Ambulators and Crossfire do that already, in a way.