I hear this 60-80+ hours of work etc is a myth, maybe it once was like that, but that most studios now make sure their employees are healthy, its just better for business in the long run...
Personally, I've only worked at one small studio, and before that one smallish (150 ppl) software company with focus on ui design and tech, so don't have much to compare with, but I've never been expected to work more then 40h/week, not even during "crunch".
I have gotten in some trouble for "working too much" though...
It's true that the pay might be a bit less then I'd have in a big corporate software company, but on the other hand I have a lot more freedom in how and where I do my work.
And I usually can get off work for a day or a few just giving notice the day before. (they get a bit cranky if I just mail them in the morning... )
And no brain-dead processes and corporate bullshit that sap the life out of you...
(I've had my share of it being a contractor for most of the major mobile phone manufacturers..)
For me, a day mostly is writing code, ticking off stuff from my todo-list, finding issues and writing new stuff on my todo-list.
Then discussing with my colleagues, or they come and ask me about something.
Someone shows a demo of what they are doing, and people give feedback...
Then if needed, some head into a conference room and discuss something in detail.
Then we go back and code some more, or research something, or draw some stuff on a paper...
Then repeat.
No-one tells me exactly what to do, its more along the lines of "This doesn't work, can you find out why and fix it?" or "Wouldn't it be fun if you could do X in the game? lets try it" etc.
My current task is "Port this game from iOS to Android and OSX" and I have a 3 months to do it. (well, it was kind of my own idea... )
They do expect me to show some progress in the meantime though, not just disappear for 3 months
Plus, I'm also involved in the design process of our next game, and constantly give feedback on others work, and help them when they ask.