A Tetris game that uses the Impact.js game engine written in JavaScript.
Demo: https://www.cmaas.de/tetris/
Tutorial: https://www.cmaas.de/tutorial-tetris-with-impact-js
Get the sources, download Impact.js (you need a license), unzip it. You have a folder in there called impact/lib/impact that contains the engine's source code.
Copy it and place it in the Tetris source code under lib/.
There's a text file showing the right location.
Have fun.