Recreation is over. This cavern is even deeper and more dangerous than the third, although it is less labyrinthine. Here your jumping skills will be tested. In the ceiling above you, you will find some stones and two mushrooms. Some small skeletons will attack you, but you should take them out without a problem. Then proceed to the right. Leave the pink rock alone, dig the loose soil and throw a ladder into the next small precipice, being careful not to fall. Go down the ladder and on the left you should find some dynamite. Then go back up and proceed to the right. Dig down and to the left you will find a ladder and a diamond. Go back to where you started the level and go down by digging the loose soil below you. On the right you will find another diamond. At this point, in the void in front of you, you should see a kind of pink platform pass at regular intervals. This platform will act as a lift to this level. You will therefore have to jump on it, being very careful not to fall into the void, or you will lose a lot of vital energy and perhaps a life. You may have already noticed a pink ghost flying around the cave: stay at a distance. If it grabs you, it will plunge you into the void, almost certainly killing you. The only way to kill this ghost is to use dynamite, however after a while it reappears, so it is better to just avoid it rather than waste a precious dynamite.
Using the moving platform, go to the ledge on the right, slightly lower. You might find dynamite. Then go down the tunnel and hit the pink rock at the bottom to make it fall. Go down and on the right you will find two mushrooms in the ceiling. Then dig the loose soil beneath you. You will end up on the pillar, but you can also wait to press it. Instead, it is important to drop the pink rock on the right. Then use the pink platform again to move to the left of the central void. You will find a large area of loose soil and a pink rock in front of you. Digging upwards you will find dynamite and two mushrooms. If you also want to get a diamond, do the following: activate one of the mushrooms then, after taking it, go down and hit the pink rock with a kick, to move it to the side (do not let it fall down). You can then go down the tunnel and find a diamond. On the left, then dig down and go down. When you fall, you will lose a couple of bars of energy, but it is a tolerable loss. You'll find another dynamite here. Then jump again on the pink platform, when it arrives, to move to the right, where you might find another dynamite. Go down a little further, using the pink platform and jump to the left, where there is a wall on which you can climb.
On the left you will notice two pink rocks. You will have to drop first the lower one and then the upper one, obviously hitting it from the side. On the left you could then find another dynamite, as well as a mushroom and a pile of stones in the ceiling. Then dig the ground beneath you. On the right you will find another mushroom in the ceiling and maybe a dynamite. Go back upstairs and use the pink platform to go down to the bottom of the cavern. On the right you will find a diamond, while on the left, if you have acted as described, there will be three tilted pink rocks, which will allow you to reach the opening on the left. The exit door of the cavern is just beyond that opening. All you have to do now is go back up using the pink platform, press the pillar, go down again and quickly reach the door. You should do it in a short time, to have even over 40 seconds on the timer.
Note: alternatively, to reach the exit door you can also throw two ladders in succession from the gap immediately to the right of the two pink rocks mentioned above. You can do it to speed things up or in case you made a mistake in dropping the rocks.