Costume Quest 2
18 Achievements
1,000
8-10h
Cosmonaut
Found the Solar System
50
3.65%
How to unlock the Cosmonaut achievement in Costume Quest 2 - Definitive Guide
You are able to go back to the past.
Speak to the NPC with the Jefferson next to the Portal. He will give you a Mystery Candy. You need to plant this and return to the future via the Portal and speak to the NPC in the top right hand corner.
Speak to the NPC as Jefferson
After that point you will need to equip the following Costumes in the same party.
UPGRADED Hotdog
UPGRADED Wolfman
UPGRADED Superhero
Then talk to him as every Costume without changing any of the Costumes. He will then give you Fertilizer.
Return to the past and use the Fertilizer on the Plant and return to the future.
No make your way to the back entrance of the research labs and go upstairs on to the top of the building and make your way into the Tree via the Door.
Walk up the inside of the Tree and out and you'll find the Chest with the Costume inside.
Credit to GuidesForUsAll for the video.
Step 2 is to upgrade the hero, hotdog, and wolfman costume.
So assuming you don't have the wolfman costume you will have to follow claw marks across town by using the wizard wand to light up the secret footprints and find more claw marks until you find the wolfman on a roof.
Now with all of those upgraded talk to the gardener in the final area of the game with all upgraded costumes on to get fertilizers and end step 2.
Step 3 is to use the fertilizer on the plant in the past and come back to the future. Now you must enter the large tree and travel up into space to find the solar system costume to unlock this crazy trophy.
Play through the story until you reach the point where a time portal in the sewer opens, allowing you to freely travel between the past and future.
Jump through to the past and talk to the NPC next to the portal. Equip the Jefferson costume and use its power to persuade him into giving you the mystery candy. Plant the mystery candy in the pile of dirt just above him.
Return to the future and find the gardening NPC named Dirtonian in the Dental Compound area. Use the Jefferson costume power on him as well. He wants you to help him remember a movie he saw once. You need to equip costumes related to the hints he gives you.
Equip the 3 following costumes:
- Superhero
- Wolfman
- Hot dog
Upgrading these three costumes is also required. Upgrades can be purchased from Shady's secret shop. Once you have them all, talk to Dirtonian until he gives you the fertilizer.
Next, return to the past and use the fertilizer on the planted seed. Go back to the future again and you'll see it's turned into a massive tree. Go through the research lab stairs and find the entrance into the tree. After ascending to the very top, you'll find the complete Solar System costume in a chest.
You will need an upgraded Hot Dog costume, an upgraded Superhero costume and an upgraded Wolfman costume. Anyone in your party can have the required costumes equipped but you must have all 3 equipped at once to progress the quest beyond a certain point, which means it can't be done with 2 members in your party. Once you get to the part in the storyline where you have to travel back to The Past for the Orel's Eyeballs quest via the Timehole to the Past, there will be a kid standing near the Timehole. Talk to him. Afterwards, use the Jefferson costume's exploration ability on him and you will get a mysterious candy. Walk over to the nearby dirt mound to toss the candy in it, which will then cause a baby tree to sprout.
The next part should be done if you have 3 members in party. You can come back later if you don't. Head back to the Dental Compound in the future and speak to the Dirtanian NPC on the East side of Dr. White's Inner Sanctum. After talking to him, use the Jefferson costume's exploration ability on him to begin the process of helping him remember the name of the movie. After some dialogue is exchanged, have all 3 costumes equipped and speak to him. Continue speaking to him after each dialogue until he gives you the Leftover Fertilizer. Now return to the baby tree in the past and fertilize it. Return to Dr. White's Inner Sanctum past the guy that gave you the fertilizer. There is a side entrance to the back area of the Research Lab. Once in go up the stairwell and exit back outside. Head south and you will see the tree with a bunch of pink leaves. Follow the twisting branch path up to the tree's door and smash it with your pail. Once inside follow the spiral path to the exit at the top. Once outside, straight ahead of you will be a loot coffin containing the Solar System costume.
Credit to GuidesForUsAll for the video.
Play through the story until you reach the point where a time portal in the sewer opens, allowing you to freely travel between the past and future.
Jump through to the past and talk to the NPC next to the portal. Equip the Jefferson costume and use its power to persuade him into giving you the mystery candy. Plant the mystery candy in the pile of dirt just above him.
Return to the future and find the gardening NPC named Dirtonian in the Dental Compound area. Use the Jefferson costume power on him as well. He wants you to help him remember a movie he saw once. You need to equip costumes related to the hints he gives you.
Equip the 3 following costumes:
- Superhero
- Wolfman
- Hot dog
Upgrading these three costumes is also required. Upgrades can be purchased from Shady's secret shop. Once you have them all, talk to Dirtonian until he gives you the fertilizer.
Next, return to the past and use the fertilizer on the planted seed. Go back to the future again and you'll see it's turned into a massive tree. Go through the research lab stairs and find the entrance into the tree. After ascending to the very top, you'll find the complete Solar System costume in a chest.
The main condition: you must have upgraded hot dog, superhero and werewolf costumes.
To begin with, you need to go to Timehole to the Past, go to the past. There will be a boy standing near the portal. You need to use Jefferson's diplomacy ability on him and he will give you a strange candy. It needs to be planted nearby in a pile of earth
Next, in the composition that I named above, you need to go to the DirtanianNPC (in other words, the gardener), who is located in the east of the DentalCompound map. And talk to him until he gives you the bottle.
Afterwards we need to go back in time and water the sprout that we planted from the liquid.
Next, we go back to the future and go to the roof through the back door of the laboratory, and then up and on top of the suit and trophy.
There is a video for clarity - https://www.youtube.com/watch?v=25wykqdX72A