The coal thing is intended - there is a way to avoid being killed by the coal (rot13: cerff m gb ragre gur pensgvat zrah, gura cerff gur neebj xrlf gb zbir gur pbny oybpx jvgubhg zbivat gur cvax oybo)
Collecting higher-tier materials requires crafting pickaxes first (which is not explained in-game)
It sounds like the tutorial messages I put in still don’t make things very clear - sorry about that! I think I’ll make a short explainer video. Thanks for the feedback and for checking my game out!