I recently played all the way through the following games on the hardest difficulty.
| Total playtime | 65.9 |
|---|---|
| Half-Life | 33.8 hours |
| Half-Life: Opposing Force | 8.2 hours |
| Half-Life: Blue Shift | 3.6 hours |
| Half-Life 2 | 11.6 hours |
| Half-Life 2: Episode One | 3.8 hours |
| Half-Life 2: Episode Two | 4.9 hours |
I have played through all the games before, but it’s been years. I didn’t rush through any of the games. I didn’t look in every nook and cranny of each level, but things that were interesting, I investigated.
I must say, the whole Half-Life series is a blast to play. I am, however, disappointed at how much shorter Half-Life 2 was then Half-Life 1.
I would be very interested in knowing how you timed your playing, and over what period of time—days/weeks/months the 33.8 hours happened in?
@Robert Bruner: Steam keeps track of how long you play each game.
I played Half-Life over about 10 days, IIRC.