Self explanatory

treasure_hunt_generator.sh

#!/bin/sh

if [ -d treasure_hunt ]
then
    rm -r treasure_hunt
fi

mkdir treasure_hunt

echo 'Aye aye mate! Welcome to the treasure hunt!' >> treasure_hunt/README
echo 'Find the keys from each island to open the treasure box!' >> treasure_hunt/README
echo 'First collect the keys here.' >> treasure_hunt/README
echo 'Then put them all in a single file named `key`' >> treasure_hunt/README
echo 'Run `sh treasure_box.sh to test your fate!`' >> treasure_hunt/README

mkdir treasure_hunt/island{A,B,C,D}
mkdir treasure_hunt/island{A,B,C,D}/region{0,1,2,3}
mkdir treasure_hunt/island{A,B,C,D}/region{0,1,2,3}/area{0,1,2,3}
touch treasure_hunt/island{A,B,C,D}/region{0,1,2,3}/area{0,1,2,3}/junk

echo 'Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.' > treasure_hunt/keyA
echo 'Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.' > treasure_hunt/keyB
echo 'Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.' > treasure_hunt/keyC
echo 'Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.' > treasure_hunt/keyD

cat treasure_hunt/key{A,B,C,D} > treasure_hunt/.hidden_key

for ID in {A,B,C,D}
do
    DIR=treasure_hunt/island${ID}/region$((RANDOM % 4))/area$((RANDOM % 4))
    rm ${DIR}/junk
    mv treasure_hunt/key${ID} ${DIR}
done

echo '#!/bin/sh' >> treasure_hunt/treasure_box.sh
echo 'if [ ! -e key ]' >> treasure_hunt/treasure_box.sh
echo 'then' >> treasure_hunt/treasure_box.sh
echo '    echo Find the key first mate!' >> treasure_hunt/treasure_box.sh
echo '    exit' >> treasure_hunt/treasure_box.sh
echo 'fi' >> treasure_hunt/treasure_box.sh
echo 'DIFF=$(diff key .hidden_key)' >> treasure_hunt/treasure_box.sh
echo 'if [ "$DIFF" ]' >> treasure_hunt/treasure_box.sh
echo 'then' >> treasure_hunt/treasure_box.sh
echo '    echo You have failed to open the treasure box.' >> treasure_hunt/treasure_box.sh
echo 'else' >> treasure_hunt/treasure_box.sh
echo '    echo You have successfully opened the treasure box!!' >> treasure_hunt/treasure_box.sh
echo 'fi' >> treasure_hunt/treasure_box.sh

echo 'Ready to go hunting! `cd treasure_hunt` to get started!'
echo 'Some hints are in the README file so try `cat README` or `less README`.'