ТЕТРИС SEMIPRO-68k is a fan-made clone for the X68000 platform, with its rules based on Sega's arcade version. It is also commonly known as Shimizu Tetris, after the author's name, Jun Shimizu (清水 順; The pronounciation of this name is not exactly certain due to Japanese Kanji characters having multiple arbitrary pronounciation possibilities). The game features a wide variety of configurable aspects, many of which influenced the design of the later Tetris The Grand Master Series. It is especially notable for being the first known implementation to feature 20G gravity (here referred to as "20cell"), that is, pieces falling all the way to the bottom of the well in a single frame.
The Cyrillic characters in the title is the proper Russian notation of the word "Tetris", as opposed to the mock-Russian notation used in some early games.