Scroll to the right until you see the large hole in the ground and the view will automatically descend to the cavern below. Click on your desk to wake up and collect your mail for delivery, then walk to the right to start your adventure.
Walk over to the shrouded blue creature and give him the first letter Starting the round. In the small subsequent scene, click on the letter to open it (you need to do this every time you deliver a new letter).
Go through the passage just above and to your left. Click on the small pink creature to the right; you should always click on the small creatures you find to ensure you receive one of the final achievements. Click on the larger partially hidden creature in the bushes and it will come up to the surface (unblocking a different path). Give him a letter.
Continue left from here to a screen with several small waterfalls. Click on the small creature with flaming hair, and it will follow you. Lead it over to the ropes on the right, and it will burn these, releasing a boat down to the water below. Click on the creature washing dishes, but it will ignore you. Return right and go up to see one creature smoking a pipe and another hiding in the bushes. Click on all 5 birds on the leaves. Click on the creature in the bushes until it finds a hiding spot directly to the right of the smoking creature. Now click on the smoking creature and it will throw its pipe and hit the other one. After it emerges from the bushes, give it a letter.
Walk all the way down to the bottom of this area and click on the two creatures talking to each other. Continue down further, then enter the triangular cave opening to the left. Down by another building now, click on the smoking pot to the right and a shaman will appear. Give him the next letter.
Click on the heart-shaped bug to the right, and then the firefly on the left. About now you will receive an achievement for interacting with 5 side characters Curious. Go through the right door of the building here to appear on a ledge up to the left. Click on the mother creature with its babies, and the firefly will leave her and go to the creature with a stick on the opposite ledge. Also click on the babies. Return into the cave opening to reappear at the building, then go through its left door to appear up on the right. Give the creature with the stick letter number 5.
Climb down the hole on the right to appear on a ledge below with more of the heart-shaped bugs. Head around to the right to find a new area. Walk left and climb down the hole in front of the nest; you will end up popping up into the nest, scaring the birds away, and getting them to break open a new path elsewhere. Click on the fisherman to the left, then return to the right. Climb up, go through the triangular cave opening, into the right doorway of the building, and then off-screen to the left.
Walk through the village and interact with every creature you can find. Make your way down to the bottom house and enter the hole just outside it. Click on the various creatures throughout this cave system, and make your way through an opening to the right. Continue to the left towards the large multi-eyed bird creature. When you get close, you can only slowly move forward until the creature relaxes. Now give it a letter.
Return to the right and go through the right cave entrance, then go to the right once more. In the next cave, click on the small creature with flaming hair, then lead him to the dry twigs just above and he will burn them. Up above in the village, this will make a large fox climb up on to the roof of one of the houses. Return back through all the caves and go all the way to the top left, then take the exit on the right to return to the first creature you met. Go through the opening just to its right.
Click on the 3 tiny birds and the 2 large birds. Click on the small creature to the right - it needs water. Click on the next creature up to the left and it will make you start crying. Visit the first creature again, then deliver another letter.
Go back and visit the crying creature again, then walk up and cry into each of the 3 water jugs to fill them up and their corresponding ponds. Flowers will bloom up higher and bees will go to the flowers. Click on the red bird to the left and the small rat-like creature to the right. Now click on the creature holding the beehive and give him a letter.
Walk to the left, then enter the hole in the side of the boat. Click on the creature to the right, then deliver a letter to the creature on the left.
Leave the boat, then continue right and go into the entrance at the top right of the screen with the bees. Climb down the hole, then walk around the new cavern. When you are blocked by a small chick, click on its mother and then walk past while you can. Continue right and click on the small creature with flaming hair, then on the fireplace to the left. Now deliver a letter to the creature nearby.
Go through the opening into a new room above that contains lots of pots. Click on the small green creatures and a larger creature will stick its head up through an opening; put the cover on this opening. Repeat this a second time and cover another opening. Repeat a third time, then give the larger creature a letter.
Go through the opening to the right and you will emerge near the village again. Click on the pillow just above you to the right, and it will fall down to the ground. Sit on it and a new creature will appear behind you. Deliver a letter to it.
Unfortunately there is no way to get directly to the middle of the village from here, so make your way back through the room with the pots, past the hen and chicks and outside. Go down along the path past the birds to emerge in the first cave again. Go through the cave opening to the far right, then another to the top left.
Now that you are back in the village, enter the house that is currently being painted, and you will exit through the house with the large fox on the roof. Climb inside the tree here, and you will reach your final destination Traveler.
Click on the creature playing the flute at the top of the tree and it will play different pieces of music. Make sure you listen to all the different tunes (either by clicking several times, or by leaving and returning to this location) Music Connoisseur. Click on the red birds to the top right; by now you will hopefully have interacted with every side character in the game Persistently Curious. Click on the opening in the building, and another creature will emerge from the bushes, so you can deliver your final letter Delivery Done.
Back in the main cave, take the path down towards your starting mail room.