Open Sorcery: Sea++

A huge, puzzle-filled adventure through multiple domains of the "deep web" - a metaphysical aquatic/internet/innerspace ocean, as you try to recover your memories and piece together your identity, while looking for a way home. This is a stand-alone game set in the same world as Open Sorcery, but no knowledge of previous games is required.

This time you play an actual "open sorcerer" rather than an elemental spirit, so as well as the traditional "matter/motive" element-based puzzles there are spell-casting and inventory puzzles, word-search puzzles, rearranging blocks of text into the right order, changing descriptions to make them consistent with each other, navigating complex dialogue trees, card games, alchemical crafting, and so much more, with almost every puzzle having multiple possible solutions.

A basic completion run takes over 15 hours, and that's without trying to get the numerous achievements, and skipping a ton of optional content. This is combined with a great story and great writing, veering between very funny, thrilling, and deeply sad with aplomb. It also looks and sounds great, with music, sound effects, occasional graphics, and beautiful typography throughout. A commercial game well worth the money, though if you just want to try it out, A Murder in Fairyland is a small-ish chunk from the middle of the game released for free.