1-5: Break the boulder and dig through the blocks. Avoid the falling boulder after digging through block 5.
6-9: Dig through the dirt and avoid falling boulders after clearing blocks 6 and 7. Grab the bronze key.
10-13: Dig through the dirt and gravel and use your bronze key to open the bronze door.
14-20: Dig through the bottom layer of dirt, then the top layer, avoiding all falling boulders. If the blob has been smashed, it may not be necessary to dig out block 19. Grab the silver key.
21-22: Open the silver door with your silver key. Dig out block 22 and avoid the falling boulder.
(Uses 21 energy)