Undoubtedly the
strangest
crossword game I've ever played.
This was a suggestion in the set of IPA refrigerator magnets called Magnetic Phonetics
(similar to the various poetry and other sentence building magnets
where you get a large bunch of tiny magnets in one box).
At the 1999 National Puzzlers League convention, we played this game
once. You play on an essentially limitless board, with no
special bonus squares, but phonetically with the IPA symbols.
Most of the players needed a cheat sheet to keep the
vowels straight, and even then, many times there are two choices
for a vowel that both fit to make the same word. The tiles had values
ranging from 1 to about 5 for rarer sounds like the "zh" sound in
"treasure", syllabic l like in "puzzle", etc.
Not an everyday game, by any means.