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