It's kinda hard to get an overview of where you have already exhausted a gold vein, when those "BAD" signs disappear after 1 day. Maybe you could include a toggle to switch between a display with and without signs?
I can't count the number of heroes that died in my dungeon, because instead of going to the exit, they HAD to turn back and try to explore all the traps they left out...
My level 17 Thief managed to get me a gold medal still, but I only got him at day 20, after countless other heroes fell to the endless traps.
 "Boom Town"){kind=icon}
 "Arzea"){kind=icon}
 "Alienocalypse"){kind=icon}
 "Dungeon Developer"){kind=icon}
 "Chaos of mana"){kind=icon}