I've sometimes wondered about using Forth-style stack manipulation as the basis for a game, and it's nice to see someone do it. These are the things that weren

I've sometimes wondered about using Forth-style stack manipulation as the basis for a game, and it's nice to see someone do it. These are the things that weren't clear to me, and that I had to spend a couple of minutes randomly clicking around to figure out (bearing in mind I'm somebody who already knows what a stack machine is supposed to be doing): - "proceed to the next level" means: click the up-arrow at the bottom right of the window. - Levels are completed by filling in the grey tiles in the centre of the window, and running the program. - Filling in those tiles is done by draging smaller grey tiles from the top-left corner. - The program can be run by clicking the right-arrow at the bottom of the window. - The first proper level (called "0_0", as far as I can tell) is already complete, the reason you can't do anything is because there's nothing to be done.