Once outside, you can try to head to the Snow Sanctuary to the northwest. However, you will encounter some Bullbos that keep hitting you. The train whistle doesn't make them leave you alone. Zelda tells you to stop at Castle Town and talk to Alfonzo, so do that.
In town, you can go into the building in the southeast corner of town if you want. It has the Take 'Em All On challenge, where you get to fight many rooms full of enemies, eventually fighting Stagnox again at the end. You won't find any hearts during your battles, and potions don't work here. If you win, you get a heart container.
Go to the post box in the north part of town. You will get a letter from Alfonzo. He wants you to take him from the castle to Aboda Village. Go north into the castle.
From the entrance, go left, and then go north to the door. Alfonzo is in this room, standing next to the beds. He has an idea for giving your train some extra power to defeat new enemies. Go back to the train platform, where Alfonzo will be waiting.
On the way out of the castle, you will pass by Teacher. After you talk to him, he will decide to leave and go look for Zelda himself.
Back to Aboda Village
Talk to Alfonzo on the train platform and agree to return to Aboda Village. When you get back to the village, Alfonzo will say that he'll work on the train and ask you to talk to Niko while you wait.
Obtain the Stamp Book
Go talk to Niko and agree to do a favor for him. He will give you the Stamp Book. Your task is to find all of the stamp stations around the world and stamp your book with each one.
There is a stamp station right here in Aboda Village. It's to the left of Alfonzo's house and the tree with the beehive. Tap the stamp station and then stamp the book. A page can only fit one stamp. If you want to redo the stamp, just tap the page again and the stamp will move to the new spot that you stamped.
When you are ready, walk over to the train platform. Alfonzo has added a cannon to your train. Talk to Zelda and board the train. Set your course for the northwest path that goes off the map.
On the way, you will find a train platform that is not marked on the map. Stop there to find Rabbitland Rescue.
Talk to the guy in the bunny suit by the entrance. He will explain that there are bunnies out there in the wild with no home. Agree to frolic with the bunnies, and the guy will give you the Rabbit Net.
To use the net, you first have to find a bunny hiding behind something while you're riding the train. You can blow the train whistle to make the rabbit jump up and be easier to see. Then use the cannon to get rid of the object that the bunny was hiding behind. Then you can use the Rabbit Net to catch the bunny. It will be sent to Rabbitland Rescue. You'll get prizes as you collect more rabbits.
Go to the Snow Sanctuary
Continue northwest. Use the cannon on the Bulbos. You'll soon arrive in the Snow Realm.
There is only one place on the map that you can go to here in the Snow Realm, so set your course for there and stop at the train platform. If you go clockwise around the loop, you'll see a black rabbit behind a rock just before you reach the platform.
This is the Anouki Village. Be careful of monsters on the west and east side of town. There are wolfos, and the ice chuchus will freeze you. The stamp station is on the east side of town hidden behind some trees.
In the center of town, there is a rocket statue playing some music. Tap it to learn the Song of Discovery, which reveals hidden objects. The chest that appears contains a Red Potion.
Now go to the house on top of the hill in the back of the village. Talk to Honcho and agree to help create teams. Then go talk to everyone in town and make note of their preferences. Just draw notes on the map.
Once you come up with good teams, Honcho will say that the only path to the Snow Sanctuary is a tunnel where a monster lives. That path will now be unlocked on your rail map. So go to the train platform and talk to Zelda to be on your way.
When you enter the tunnel, if you look up you'll see a crab-like monster on the ceiling. After you pass it, it will drop down to the floor and start chasing you. It's a Rocktite. You have to shoot the big eye in its mouth over and over. Just tap the eye as quickly as you can. If you don't do it quickly enough, the Rocktite will fall onto the train and damage it. After you hit it enough times, it will die and you will automatically arrive at the Snow Sanctuary.
There is an Anouki running a shop to the right of the train platform. He sells a Heart Container for 2000 rupees, as well as potions and other things.
Head north. Beware of wolfos on the way. You'll see the stamp station on a hill as you go toward the cave. Near the cave, there are ice chuchus. Use the Whirlwind to stun them.
You'll reach a cave. The sign says to reach the door without being seen. You have to press the switch and then run to the door, but you can't walk past where a statue is looking, so before you press the switch, go around and make a note of the directions that the statues are looking in. Then press the switch and walk to the door in the back without walking across the path of a statue's eyes.
After you do it correctly, you reach Steem. Perform the duet with him to make new spirit tracks appear. Steem warns you of blizzards in the area. Now you can leave.
Be careful of snowmen along the sides of the tracks. If you wait too long to get rid of them, they will throw their heads at you. To kill them quickly, aim your cannonball at its body to get rid of both its head and body.
If you head north and try to make it through the blizzard, you'll just get sent back to the beginning. Return to the Anouki Village.
Talk to Honcho and he'll tell you to visit Ferrus, who lives in the east. So get into your train and go there. Stop at the train platform that you find here.
Go into the little train car. Nobody is there, but if you tap the table in the center, you find a note. It shows the tracks to the east of Wellspring Station with some places circled. You should mark those spots on your map and look for Ferrus there. Before you go, you can tap the note on the back wall to read about warp gates. If you find one, hit the triangle at the top with your cannon.
Ride out to the eastern plains and you'll find Ferrus at one of the spots marked on the map. He'll be next to the train tracks taking pictures. Just stop the train next to him and you'll stop and talk to him.
Ferrus will show you an old map that shows the safe path through the blizzard. You'll have to blow into the microphone to get the dust off of it. After that, make a note on your map of the safe path. Then get into your train and go to the Snow Temple. Watch out for snowmen along the way.