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.
Acquire all wind essences
Acquire all spores of energy
Collect 400 crystals
Craft every skin
Rescue both lost lovers
Discover every mushroom
Beat both obstacle courses
Knock down all the strawberries
Talk to the onion
Bring both relics to the researcher
Unite both capybara siblings
Rescue Chungy
Cleanse the corruption
Beat the diver challenge
Explode the river drain
Beat the nectar gathering high score
Beat all three glider game challenges
Collect 200 crystals
Help a friend gather two acorns
Feed the lizard two berries
Restore all flower shrines
Collect 100 crystals