In order to get to level 102 to get the final Clairvoyance upgrade you will need to:
-Complete all optional missions (These are all required for other achievements and their respective guides can help if you are stuck)
And you'll need to collect:
Places (4 main open areas of the game)
- Every Psi Challenge Card (27 in each Place except the Quarry which has 18)
- All 24 Psi Challenge Markers
Brains (13 in total)
- All Figments
- All Nuggets of Wisdom
- All Memory Vaults
- All Emotional Baggage
Quick Guides on Youtube has an excellent video series detailing all collectibles in each of the Places and Brains. There are time stamps for each item in the Show More notes.
I'll post the vid for the first level. If you wish to see them all on TA without going to Youtube, check out the Figment acheivement:
You can either go to their page and click on Playlists to find the "Psychonauts 2 100% Collectibles" playlist of follow this link here and search for it:
"
https://www.youtube.com/channel/UC_k8qUvgIFLoODu370mLBoA/pla...The most frustrating-to-find items will definitely be the figments as some of them are quite tricky.
Some tips when looking: go into that Brain's page in your menu and press
to look through your figments to see if there are any duplicate ones you've missed. That way when combing the videos you can just watch carefully to see when they pick up the ones you need. If it's a duplicate it may also help you narrow down the area it's in. For instance, if it's a banana in Bob's Bottles, look in palm trees on the islands (that banana drove me crazy, ha).
I also set the speed of the video to 2x which was really helpful for speeding up the process.