After passing the level and continuing to play, you will find the plot: a man enters the cave of Jibairut Pas. You go to the cave and talk to the man. After triggering the plot, he will give you a shovel. The shovel can remove slates and gravel, but it is recommended to reach a higher level before going there, otherwise you will not be able to defeat the boss inside. I'll practice until I'm 90 before I go again