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