Tetris (and Flash disassembly)

Vadim Gerasimov was one of three original authors of Tetris

Original Tetris for Mac can be played online on Web SE (Flash required). direct link to WebSE, direct link to Tetris

P.S. If you want to play around with flash (swf) files, look into SWFtools which is a GPL licensed set of tools for disaseembly/compression/object extraction, etc of SWF files. Using swfcombine -d file.swf -o file_decompressed.swf and strings, one can figure out what other web objects swf file refers to.