Beginning of the Cave
Start the level off by destroying the anklebiter generator to your left, and some archers in front of you and on your right. Grab the x-ray glasses next to the anklebiter generator that was just destroyed. The chest on the right is a random potion chest. Walk to the right, kill off the golem, and grab the keyring it drops. Kill off some annoying grunts that come from the left, and grab the purple crystals. The chest in the middle of the path has a red death inside of it, so use a potion on it to turn it into an apple. Avoid the fire trap, and kill off some grunts and destroy their generators. Go to the left and destroy the anklebiter generator, along with another grunt generator just a little above that. Go back to the right for a bit to destroy another generator, and open the chest with a steak inside. Kill the bomb thrower on the bridge, and open up the barrel for a hint scroll.
There are quite a number of chests in this save, so the x-ray glasses are a helpful thing to have on. Go back to the left side, and on the left-most wall, there is a rock that can be destroyed. Destroy it, and kill off the general walking around inside. Pick up the reflective shield that it drops and walk downward and to the right to find a green crystal and a chest that has a keyring inside. Backtrack up to where you destroyed the wall, and this time go up. Avoid the fire traps and kill off the bomb thrower in the distance. Grab the purple crystals on the side as well. Go to the top part first, and open the chest to get a turbo power-up. Go to the left and destroy the rock. Walk to the top to get a green crystal. Walk downward and open the first chest to get some treasure. Kill off the anklebiters and destroy their generator, then open the second chest to get some more treasure. Grab the one blue crystal in the corner and backtrack to where the path originally split, right before the turbo power-up chest.
Middle of the Cave
Go to the right path this time and kill off the anklebiters, and destroy their generator. Go to the right and grab the golden icon just sitting there. Go upward and walk over the fire trap, and deal with the archer that is attacking you. Grab the key on the left, and open the chest on the right for some ham. Walk on the path going up to find a generator and an explosive suicide grunt. Take care of both and open up the chest for some levitation wings. Grab the purple crystals on the path to the left and open the chest all the way to the left to get a keyring. Destroy a fake wall down below and kill off some anklebiters and destroy their generator. The chest on the top contains some treasure. The middle chest has some more treasure. The chest near the lava is just junk, so you can ignore that.
Backtrack to where the path split and go upward to find some grunts coming out to attack you. Destroy their generator and grab the pair of x-ray glasses. Destroy the fake wall in front of the fire trap on the left and kill the bomb thrower and anklebiters in here. The chest on the left contains a cherry, pineapple, watermelon, banana bunch, cherry, spoiled fruit, or an apple. The chest on the right is another random potion chest. Walk out of the secret and move towards the right to find a fire trap on the wall with some purple crystals on the path. Grab the purple crystals and kill the anklebiters along with the generator. Grab the key and keep moving on.
End of the Cave
Kill off another anklebiter generator and kill an archer a little down below. There is a chest right below the generator, which contains a keyring. Before moving on to the right, go to the most top corner where you can see a random fire trap. The wall behind this trap is a fake wall and can be destroyed. The secret has an invulnerability in the chest, and an ice crystal behind it. Now go to the right and destroy some generators and kill some more enemies. Walk to the right to find a keyring and a chest at the top right corner. Ignore the chest as it contains some poison fruit.
Go down and destroy the anklebiter generator, and kill the bomb thrower. The top most chest has a keyring inside, but ignore the bottom chest as it's only a bomb. Walk down and kill off an anklebiter generator. Grab the purple crystals on the path above it, and then kill off some grunts and their generators, along with a bomb thrower. On the right, there is a blue crystal and a chest with some fire breath inside. At the end of the path is a lone archer and a fake wall on the left that can be destroyed, which is just a shortcut back to the otherside. The chest is another random fruit chest just like before. Grab the purple crystals on the edge and kill the grunts and their generators above that. The chest by the lava has a reflective shield inside. Before walking across the bridge, destroy a fake wall to the right of it, and kill all the grunts and their generator inside. Grab the blue crystal and keyring below. Open the chest next to the barrel for a cherry. Open the barrel for the second and final hint scroll of the level.
If you explored every part of the level, you should have found many keys and keyrings both outside and inside of chests. Continuing on, walk across the bridge to the right and destroy an anklebiter generator in the distance. Destroy a fake a wall on the top right as well, which has a grunt generator, a chest, and a blue crystal. Grab the blue crystal in the back and open the chest in the front for a keyring. Walk to the right while avoiding some fire traps, and destroy another anklebiter generator near the exit. If you still have the x-ray glasses, peek inside the random chest to get the item that you want, then exit the level.