Yeah, I almost puked after playing for a couple of hours last night. For some reason, Half-Life and Half-Life 2 make me sick more than any other FPS's. I don't know what it is about them.
I get motion sickness from playing Half-Life. I played HL:S for a while yesterday and it made me sick. It is the only game that I can think of that does it to me. I haven't noticed it with HL2 yet.
I think it is about the right length.
Surprisingly, it is much shorter than Vampire: Bloodlines though.
From an interview I just read (http://planetbloodlines.gamevision-network.de/bloodlines/intervieweng.php):
I played CS:S a bit yesterday and really didn't care for it. I liked HL DM (Bounce was my favorite map). I like being able to just hop on a server and play for a bit and then leave without coordinating with teammates.
Apparently you are supposed to talk into your monitor when they ask you questions to help with the immersion. And you are supposed to put your hands on the monitor when picking things up so the objects are not just floating in front of you.
I, obviously, don't agree with this design...