So I played many hours of this at the tail end of the beta, but got distracted by school when it released so haven't played till now.
Took my first couple of spins in the Engi ship, and actually just had my best game yet, making it to Sector 5 with a fully upgraded drone system with a Defense Drone II, Anti-Ship Drone II and System Repair Drone I, and in the first sector I got a Halberd Laser, so I was just ripping through everything, and I had upgraded my shields to level 2.
However I kept running low on fuel because it was very scarce in this round for some reason, despite me buying all of it that was available. Then I got stuck in a civilian galaxy that was very unfortunately laid out so that you HAD to go around clockwise to get to the exit, but you can get most of the way there before finding that out. I had to face the Rebel fleet twice, both times within a nebula, and then just before reaching the exit (where I would have ran out of fuel anyway, admittedly) This super powerful Rebel ship showed up out of nowhere. It kept setting everything on fire and taking out my oxygen so I was in a constant struggle trying to keep my guys in a safe place while suffocating the fire and keeping my oxygen high enough simultaneously, all the while trying to keep enough systems online to keep my very weak hull from being taken out.
Of course, it was like trying to take water out of a sinking ship with a teacup because they would keep burning all of my stuff and they finally pierced my hull. I had to quit and take a break, but man, it's amazing how a great run can turn to shit because of one navigational miscalculation, and that's what makes this such a great game.