And the basic method for introducing outside code into NES Tetris has been publicly theorized since at least 2021 when players were investigating the game's decompiled code. (HydrantDude ...

The source for both the Lua version and a Java version of the code is available ... except the Tetris ROM. If you’re interested in how 8 bit games were built, this dissection is a great read.

but the MIT team just pulled ahead by issuing the source code of the big hack. In case you missed it, a group at MIT turned one side of the on-campus Green Building into one big Tetris game ...