My version of the 2048 game that was written by Gabriele Cirulli originally here.
How it works is described here.
There is now a completion panel for both losing and winning, with a restart button.
It only inserts one number after each move, except at the beginning, when two are inserted. I'm not sure why I thought that it should always be two.
It's no longer possible to make more than one move between numbers being inserted. The delay between redrawing after a move and inserting a new number and redrawing again was originally a debugging thing, but the effect is nice.
I have now added scoring. The score is added to whenever two blocks coalesce.