Use a key to enter the coal mine in the island at north 77. The inside is very dark and full of coal piled up. So you need fireflies and the strongest shovel.

Find a island at north 77

Unlock the door with the key

Bring fireflies and strongest shovel

Survival Island 2

"Survival Island 2" is a free escape RPG game that anyone can enjoy playing.　Your goal is to escape from the desert island by solving problems.