I really don't expect anyone to get this with what little I can remember but it would be great if someone could 
It was either second half of the 80s or very early 90s when this was released.
I remember there was a group of characters --possibly aliens, possibly humans-- that found themselves transported or maybe woke up on an alien world.
I think the world was either completely flat or possible a cyclinder or ring type construct, and I remember them saying it was much bigger than the surface of earth and the entire world was artifically constructed.
The one part I do remember about it, was one of the characters tried to drink some water out of a stream - and immediately threw up because of the water was teaming with life and bacteria, and they realised they would have to boil the water...
The whole world was alive with plants and insects to I think...
That's about all I can remember - I know its not very specific but perhaps the section about the character throwing up will help.
...
It was either second half of the 80s or very early 90s when this was released.
I remember there was a group of characters --possibly aliens, possibly humans-- that found themselves transported or maybe woke up on an alien world.
I think the world was either completely flat or possible a cyclinder or ring type construct, and I remember them saying it was much bigger than the surface of earth and the entire world was artifically constructed.
The one part I do remember about it, was one of the characters tried to drink some water out of a stream - and immediately threw up because of the water was teaming with life and bacteria, and they realised they would have to boil the water...
The whole world was alive with plants and insects to I think...
That's about all I can remember - I know its not very specific but perhaps the section about the character throwing up will help.
...