It might be, that everybody was excited, while Steam ended with downloading the game. You just need to press the button "Play" to play the game and enjoy it with Sam, Claptrap and especially with Glados.
The only problem is..... IT DOESN'T WORK!
Like the first game Poker Night, the second game has the same EXE problem. It doesn't work. The game crashes immediately while the screen is loading. It is a shame that Telltales make the same mistake. I guess that a speciall prefs.prop data is needed.
And in addition: The save files in PN1 aren't saved.
It is not a hate. It's a fact.