I do remember the puzzles in the last rooms in VLR and ZTD being difficult but you should manage on your own if you try experimenting enough.
Honestly, even with the mild cliffhanger at the end of the last game, ZTD still ties most plot point left from the 2nd game so I don't honestly need a 4th game in the series ...
BUT, it wouldn't honestly hurt to make another one.
He's also occupied with AI: The Somnium Files (HYPE !) and another project with his studio so I don't think this will happen in a short time anyway.
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