Hi, thanks for testing our game.
We're aware that there are still some bugs in the game, but normally you should be able to dig with the "E" key at the point where the terrain is different.
Enemies begin to spawn after digging the first terrain and thus discovering the first tunnel with doors.
Buttons and mechanics can be found in the description below the game.
In the I was saying, there are still some bugs related to animations, mechanics, etc. that still need to be resolved, so perhaps you won't be able to see everything mentioned in the description at the moment or you could encounter another problem that would prevent the game from working properly.