Up to chapter 04. Oh lordy. Mild SF game/story spoilers...
I had to disguise myself as a stripper to seduce Forrest Kaysen in the dressing room of a casino called SWERY 65 while on a flying airship filled with arms dealers. I found out what the purple gas does and it is none too pleasant. Finally I was konked on the head and I don't know what happens next because my friend and I took a break by watching Tron. The boomerang cards are useless.
All in all, a productive evening was spent.
That scene really did disturb me, and because of that I loved it. It's nice to see
a virus that actually does something immediately and so grotesquely rather than, say, zombies (not like I have anything against them)
I've never used the boomerang cards, just stuck with the gun or knocking those suckers out.
In the next area, all I have to say is scale the cliffs during the narrow part. Look for broken fences for when to drop.