Here is the full list of all 24 XEL achievements.
Put an end to the madness.
Upgrade Burnhilde to the max.
Smash the revolution.
Enter the Scorched Wasteland (without burning to crisp).
Parry 100 times.
Upgrade your Clubber to the max.
Upgrade your Sword to the max.
Solve the mystery of the Science Station.
Parry for the first time.
Upgrade your ZapTrap to the max.
Upgrade Chap to the max.
Enter the Glacial Glades.
Collect all Stamina Seeds.
Enter the Bog.
Get your hands on the bio synth silk dispenser.
Travel to "that strange place" for the first time.
Defeat the rusty Overseer.
Collect all Health Seeds.
Upgrade your Webshooter to the max.
Upgrade all Gadgets to the max.
Master all cooking recipies.
Collect all audiologs.
End your adventure without any upgrades (except THAT ONE for Chap).
Collect all Achievements.