list of unlockables?

[BLÀde]

playing on the switch. I've unlocked all 11 flying presents and all the characters but in the unlockables screen there are still several presents to unlock plus a mailbox. how do i get these? is there a list somewhere telling you what to do to get everything I googled couldn't find anything.

[Nap]

One present you get for beating the tutorial. The Mailbox is unlocked by visiting every backer at least once on backer island (across multiple playthroughs). You shouldn't be seeing several other ones locked. All the presents with wings are the ones you get from the parking meters, the present without wings above the mailbox is for beating the tutorial.

[BLÀde]

there's 4 other locked presents below the mailbox?

[Nap]

Under the mailbox is the present Black Friday - this unlocks with the Mailbox once you visit all the backers. After that there aren't anymore presents in the Unlockables Menu, there are 3 characters you need to unlock.

[BLÀde]

how many backer islands is there. also are they always easy to spot like floating on little islands you can just jump on with spring shoes? or are there some hidden in corners of the map needed wings?

[Nap]

There are around 20 Backer Islands, if you go to our credits and see all the little people dancing on the bottom of the screen, those are the people you're looking for. You will always see a Backer Island from the main part of the levels, they aren't hidden in corners.

The backer on the island is always random, you don't have to find them all in one run, just land on the island whenever you see one and talk to the character, you'll get them all eventually.