Having not found a tetris clone for the PC that I really liked, here's one of my own creation. The object of the game is simple. Put the falling pieces into the pit such that they all fit together. When the pieces line up to make a row, that row is removed, leaving more space for you to keep putting pieces in. Its like putting pegs in the right holes. To navigate the menu, use the UP and DOWN arrows to move the selector up and down. Press ENTER when your selection is complete. Press ESCAPE to go back.
No installation required, just download the exe file to a location of your choice and run it.