Lemmings demo turns each line of wrapped text into walkable terrain

A web demo based on Lemmings lets small walkers move across the page itself, treating borders, buttons, images and text fragments as ground. Rather than measuring whole paragraphs as single blocks, it uses text ranges to collect separate rectangles for each wrapped line, preserving the gaps and varying line lengths. Text is treated as one-way floor that catches falling walkers but does not act as a solid obstacle, keeping tightly spaced lines from becoming cages. Coordinates are converted from viewport measurements into a coarse world grid with outward rounding so thin features are not lost, and falls are checked in small steps so thin surfaces are not skipped. The author also notes that the world is rebuilt after page changes so standing walkers stay attached to their surfaces.