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