My question is, do these npcs only work for people who have all the games installed, or will people who only bought Portal still be able to see them in maps?

Also, along the same lines, can I use any of the textures I see in hammer, or should I just stick to the ones used in portal, and self-created ones? In other words, if I use a hl2 texture, will it work for everyone who just has Portal?

Sorry if this has already been covered elsewhere.

However, for things like headcrabs etc, there would be more at work than just the models. If I put one in a map now, it will attack me, and behave like a normal headcrab, although it behaves badly with respect to portals.

I am curious if this AI behaviour would still exist for people who only own Portal.

I know a cool purpose for Gman, put him in one of those observation rooms, so you see a figure in the room watching you.

I'd like to see some of the HL2 puzzle objects in Portal...like the giant power plugs and a magnetic crane rather than just buttons and pellet catchers.