Here is the full list of all 101 Little hidden city achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
the end of the game
find wheelchair
find medical bed
find air conditioning
find solar_battery
find electric car
find traffic light
find statue
find TV
find cat
find boat_old
find satellite_talk
find power station
find basketball
find pointer
find bicycle
find telescope
find VOLGA
find camera
find slide
find motorcycle
find football_ball
find swing
find flower_palicious
find inflatable pool
find tractor
find gazebo
find sculpture_rock
find water_motocycle
complete a level gas station
find haystack
find part of the train
find engine
find hovel
find extinguisher
find barrel
find strut
find muffler
find soona
find wheel
find old car
find equipment for garage
find army trailer
find logs
find wheel_2
find spare part
find canister_2
find canister
find Jack
pass_level_supermarket
find bank_register
find shoe
find sink
find bucket_washing brush
find trolley
find soft toy
find cake_shocolate
find moped
find pac_products
find jacket
find handbag_female
find bananas
find drawer
find basket
find watermelon
find eggplants
find steak_sibs
find fish
find stool
find carton
pass_level_country house
find tools
find watering can
find bucket of apples
find log
find stairs
find watering can_2
find potty
find plant_in_roof
find light
find Boots
pass_level_busstation
find stroller
find nameplate
find newspaper
find bottles
find shoes
find bicycle_old
find suitcase_opened
find suitcase_02
pass_level_apartment
find strap
find coat
find tube
find magnifying_glass
find bag
find hat
find book
find umbrella
find suitcase
start the game