Kubikfoto3 is an interesting German agency that developed a photographic production pipeline for interactive environments. Sound pretty vague but it starts making sense if you look at the examples.
It's basically the old Point & Click formula with good photography, well-made video transitions and some very simple yet effective interactive effects at each screen.
http://www.kubikfoto.de/Being an advertising agency, their projects are mostly pretty awful content-wise. I found them by accident through this "interactive hip-hop video". The usual crap of youngsters rapping about how dangerous they are and how they kill people and such stuff.
http://www.kiz-neuruppin.de/