Syberia is a 2.5D game, Kate Walker goes to a small town to buy a "toy" factory only to discover the owner has died and there's a missing hier which she needs to find.
The whole town is driven by clockwork machines (automatons)
Its really well done, great puzzles that make you think, nice backdrops, animation and well thought of machines
The only real grumble I had was the dialog gets abit repetative, "Kate Walker" is named in every dialog exchange , also she does quite a lot of just walking around, I'd done a 1/4 of the game before I realised she could run lol
The sequel is just as good, some things where improved, like inventory and the dialog system, in the first game the convo tree didn't remove old topics which was abit annoying
Its well worth a look and I think its fairly cheap to buy now, its quite old, I had to get an update to run it on Vista, the sound played to fast and funkyness with the 3D character (her face was missing!) Syberia 2 worked fine
Anyway its a massive game and I really enjoyed it, by the end of the first game its just getting started and leaves you needing to play the second

You can still play Hitchikers on the BBC radio4 website:
http://www.bbc.co.uk/radio4/hitchhikers/game.shtmlI can't remember how far I got with the original