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