Frog y-3 is friendly to walkers. The other frogs (y-2, y-1, normal) are all deadly. Do you find this strange, too?
In particlar, y-2 has a a one-pixel air gap between belly and floor, yet is deadly. >_>;;
This image is from your replay, with a hack of Lix that shows trigger areas during play (important missing feature). The miners produce a gap, and the walking lix survives the upwards slope. In this light, do you think that the trigger is too short vertically? Too narrow? Or both? Or fine after seeing this?
-- Simon