I got up to the point I was stuck at ten years ago, then spent about an hour working out what to do from there, and another hour to complete the game. Turns out I was quite close to the end when I was 9. From start to finish it probably took me 4-5 hours (or 11 years if you count when I *started* playing) (I found the puzzles harder at the start), then I speedran it through in 57 minutes o/

Some of the puzzles are very unforgiving, like pinpoint places you have to click/mouseover just to progress. *spoilers*I was stuck in the abandoned subway 10 years ago, it took me a while to find that tiny light socket and work out what to do with it =P