2010 Jan 20, 8:56I had no idea of the amount of variation: "The Tetris Guideline is the current specification that The Tetris Company enforces for making all new (2001 and later) Tetris game products alike in form."
Covers things like piece color, vocabulary, speeds, rotation system etc etc etc. I'll be adopting some of this in Polytope Tetris...
tetris wiki reference game videogame
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