* Very long hours. At least where I was, people would seriously work 12-14 hours a day (out of which 90% would be "effective hours", churning away tons of code).
* Peer reviews, while apparently treated seriously, are in fact a half joke. Your manager is your God. You fit with him/her, you're golden; you don't, you're dead meat. Most managers seem at least alright; however, I apparently got very unlucky.
* Code reviews. I have heard many a old-time Googler complaining about the pedantry. "Code review Nazis" are commonplace. From discussions w/ other Googlers, it seems the transition from "this doesn't break anything and doesn't embezzle funds" to state-of-the-art torture has happened over the past couple years. This hurts productivity big time, and given that you're still expected to have completed a ton of work, guess what happens.. yeah, you got it: you'll leave past midnight and work from home during the weekends to barely meet expectations.
* The "transfer to any project any time you want" is an absolute myth nowadays.
Caution: from informal discussions, it seems that I really got the short end of the stick, and that in other parts of Google things are much smoother. YMMV.