Here is the full list of all 22 Smushi Come Home achievements. It takes around 4-5 hours to unlock all of the achievements on Windows.
Craft every skin
Collect 400 crystals
Knock down all the strawberries
Beat both obstacle courses
Beat the nectar gathering high score
Bring both relics to the researcher
Acquire all wind essences
Acquire all spores of energy
Discover every mushroom
Talk to the onion
Unite both capybara siblings
Rescue Chungy
Beat the diver challenge
Cleanse the corruption
Explode the river drain
Rescue both lost lovers
Help a friend gather two acorns
Collect 200 crystals
Beat all three glider game challenges
Feed the lizard two berries
Restore all flower shrines
Collect 100 crystals