Here is the full list of all 22 Flynn: Son of Crimson achievements.
Find Bax in 4 separate locations.
Using the sword, pogo-bounce on 4 separate enemies without touching the ground.
Quickly skip Bohrin's dialogue.
Completed all levels, acquired every relic and learned every skill.
Defeat Zealock
Find, collect and sell all 20 relics to Yombal.
Defeat Imbra the Shadow Sorceress.
Complete the 6 challenge stages.
Defeat Xellios the Toxic Marksman.
Defeat Rozia for the final time in the Desolate Woods.
Have an enemy frozen, burned and zapped simultaneously.
Acquire every skill from Loretta.
Have a throwable rock bounce on an enemy 5 consecutive times without touching the ground.
Perform a full plummet combo with any Crimson weapon.
Defeat a training dummy in Sanctia.
Defeat Kravios the Aquatic Voltknight.
Chain zap 7 enemies with lightning magic.
Starting with an uppercut, perform a full aerial combo with any Crimson weapon.
Defeat Bora the Whirlwind Assassin.
Acquired your first skill.
Find and collect a golden relic.
Set out on an adventure with your beloved friend, Dex.