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The Level Design Book, an amazing free online resource.
(book.leveldesignbook.com)
So many good ones in this list, cultist simulator will make you see the world through its game system afterwards, ghost of a tale is Soo damn cute and well done. Expanding on 5d chess I'd recommend 4D toys, a sandbox that will open your mind to the 4th dimension
Antichamber for a good old school mind bending puzzle game