Staryshift: Second Impact

Let's start with Area Changes
Ruins/Home- Cool Home
Snowdin- Snowdin Town / Sleet City
Waterfall- The Marsh / Cascade Temple / Cataract Town
Hotland/CORE/Resort/True Lab- Treetops / Spirit Walk / Undyne's Battle Resort / The Chamber
New Home- Cooler Home

Cool Home- Papyrus' current dwelling. He painted the ruins of Cool Home to make it seem more like an actual home rather than a space. Papyrus has also built great statues of himself. He also built one of his brother Sans but it's stashed away somewhere. Cool Home is filled with puzzles, traps, and pranks. There's even a waterslide trap that leads to a lower level of Cool Home. While the door to Cool Home is closed, there is a puzzle hidden in the bushes that tells you how to open it.
(For those who seek shelter, do not skelter. Be nice and be kind and all sorts of doors will open for you. If you think being nice is for wusses, don't knock it until you try it)

Snowdin Town- Snowdin Town is like Santa's Workshop. It has two large red doors blocking the entrance of the town. There are also magic Teddy Bear Guards who guard the entrance so no unwanted intruders get in. On the inside of the doors lies a magical place covered in blankets of white happiness. The town is decorated in Gyftmas lights and everyone is filled with joy and cheer. Up north of Snowdin Town lies the shopping district. There's also The Workshop where all the toys are made. Down south of Snowdin Town lies the Ice Cave. It's a cave made of ice and there's a large hill at the summit of the cave which many of the kids slide down on with toboggans and bobsleds.

Sleet City- Sleet City is located east of Snowdin Town. Its structure takes heavy inspiration from Chinese cities at nighttime. There are lanterns on the posts of buildings. Exotic restaurants with classy monster cuisine and various street vendors. This is the place you'd go to if you wanted to have a night out. Due to all the snow turning into ice, the citizens of Sleet City turned them into decorative ice sculptures to show off. Asriel takes you here on your date together.
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The Marsh- The Marsh is the opening to another new adventure. Toriel is lurking in the backgrounds tracking your movements. The Marsh is fairly lengthy. Its like regular waterfall up until the collapsing bridge. But of course, there are new areas to explore too. There is leaf boat that you can use to ride the water. Mikhail also tries to act as your guide throughout The Marsh.

Cascade Temple- After falling down the bridge into the junkyard, the entrance into Cascade Temple lies ahead. Mikhail is going to accompany you once again as he fell down with you. Within the Cascade Temple, there are various water puzzles that require co-operation. There are also scriptures on the wall that give insight into Boss Monsters and monster magic. The temple is lit with fire as Toriel is still watching from the shadows. After completing all the puzzles and exiting the temple, you have to navigate the swamp and climb the waterfall all the way up into Cataract Town.

Cataract Town- The town high up on the waterfall. This is where you and Mikhail part ways and say goodbye. After exiting the town, you reach Cataract Outskirts; where you fight Toriel. Toriel only has an interest in fighting you if you've killed a few monsters. If you haven't killed any, she then wants to prevent you from leaving as the journey ahead will not be a safe one. That Treetop is filled with danger, especially the vines. You have to reason with Toriel, telling her that you were smart enough to solve all the puzzles that came your way and that you'll make good choices in the future too.

Treetop- An enchanted forest. The Royal Scientist Asgore is a biologist, so the underground runs on more natural power sources along with Spirit Vines. Treetop is the Hotland replacement. Instead of the usual elevators like in canon Hotland, there are air shafts and pillows. The air shaft will float you up to the next level of Treetop. If you want to go back to the previous floor, you're gonna need to take a plumment at the hole and land on the pillow below. There are 3 levels to Treetop.

Undyne's Battle Resort- Undyne's Battle Resort is a residential area on the third floor of Treetop. It takes the place of the MTT Resort. Undyne's Battle Resort is similar to Battle Restaurants that you'd see in Pokemon. In order to get a room, you need to challenge Undyne herself in combat. The ultimate goal is not to win but to try and give it your best effort. Just like you should do in everything.

Spirit Walk- Spirit Walk is the CORE replacement. Spirit Walk is the place where Spirit Vines are harvested and turned into energy for the underground. The Spirit Vines also charge the the security system in Spirit Walk. If the Spirit Vines are overheated and overused, they can become dangerous and can send out fatal electrical shocks. Undyne is waiting at the end of Spirit Walk ready to fight you. Her battle with you is live too. To show the underground how the true heroine slayed the #1 enemy to monsters and gave them freedom.

Cooler Home- Sans' current dwelling. Cooler home is near the barrier. Its just like how the normal New Home is in canon. Its a long walk to the throne. Though it does not talk about the Asriel and Chara replacements as those are stories for another time. Sans is also waiting there in his throne room. You can explore the town in Cooler Home too. There are also some pranks scattered around Cooler Home. Especially in Sans' house. There are a few monsters in Sans' house because he's nice enough to let them stay, he often sleeps on his throne and only goes to his actual house for food.