Comcast does NOT show any of the games in their entirety.
What they do have is the "NFL Network On Demand" Service. You can basically pull whatever NFLNetwork is broadcasting for that day immediately to your face to watch.
They also have NFL Weekly Replay (and this is the closest you'll get to having all the NFL games to watch without getting the Sunday Ticket on Directv).
Each game is crunched down to specific highlights and thrown together in a 10 minute composite.
Basically, it's all the scoring with some pivitol moments.
Only 3 leagues this year. No sense in rooting for everyone in the NFL.