Here is the full list of all 31 Kingdom Eighties achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Complete Episode IV
Complete the game on Hard
Rainy day at Paradise Estate with Rainbows in tow
Destroy a portal around the mall
Get something back from the past
Complete Episode III
Defeat 10 greed with a machine gun
Lose the Crown, and take it back
Get eaten by a shark
Destroy a portal on the streets
Complete Episode II
Complete a level with only two workers
Lose 80 coins to the waters
Slap a monster truck
Recruit someone smart
Recruit someone friendly
Complete Episode I
Enter a cave
Clear all the trees on any level
Uncredited professional BMX rider making it rain coins
Wait for the bus
Destroy another portal
Destroy a portal in a forest
Recruit someone athletic
Find the missing trophy
Recruit someone handy
Complete the game on Cursed
Survive for 50 days in one level
Complete the game in 50 days or less
Complete a level with no more than 20 kids
Destroy a portal on Peaceful