Here is the full list of all 29 Goonya Fighter achievements.
Complete tutorial
Complete all stages in WORLD1
Complete all stages in WORLD2
Complete all stages in WORLD3
Complete all stages in WORLD4
Complete all stages in WORLD5
Complete all stages in WORLD6
Obtain 3 stars for each mission in WORLD1
Obtain 3 stars for each mission in WORLD2
Obtain 3 stars for each mission in WORLD3
Obtain 3 stars for each mission in WORLD4
Obtain 3 stars for each mission in WORLD5
Obtain 3 stars for each mission in WORLD6
Defeat the boss without taking any damage in Mission 1-8
Defeat the boss without taking any damage in Mission 2-8
Defeat the boss without taking any damage in Mission 3-8
Defeat the boss without taking any damage in Mission 4-8
Defeat the boss without taking any damage in Mission 5-8
Defeat the boss without taking any damage in Mission 6-8
Defeat a fighter with bombs in versus
End a round with draw in versus
Attack a fighter in the result scene
Dropkick a fighter 5 times in a round
Collected 150 coins in a single coin battle
Collected 5 red coins in a single coin battle
In adventure mode, beat your opponent by more than 2 flags in a race
Swim for 5 seconds in a row
Fall down 100 times
Collect all trophies