Fold things slowly, sometimes clues are hidden inside the folds of the pop-up buildings. You need to walk quite close to an object before your inventory appears on the right side of the screen. There are audio cues and puzzles that are solved through sound so to give yourself the best chance of hearing them turn up the volume or wear headphones if you cannot have the volume up high for whatever reason. Your inventory will appear on the right hand side of the screen when you approach an object and are close to it.