Judging from Steam and elsewhere it looks like nobody is currently playing this game.
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I solved the coordinates puzzle and now have a gate which does not open, other objects that you can't interact with. Obviously there is something more to do as I can't visit the hotel. The only possibly clues might be the plaques and flags. The stuff from the shore does not help in any way. The tower also does not allow any interaction. Is it a another case of missing a hotspot somewhere? I have spent ages looking for some action I am allowed, but nothing works. When future actions are not apparent, I start to wonder if a bug might be a factor.