It seems it was all by hand. From the FAQ: > Q. So how did you draw the graphics? > A. So for 40x48 resolution you can't just take a paint program and have it

It seems it was all by hand. From the FAQ: > Q. So how did you draw the graphics? > A. So for 40x48 resolution you can't just take a paint program and have it do this automatically. That tends to lose a lot of important details. > Usually I take a screenshot and drop a 40x48 grid on top and then trace over it.