Here is the full list of all 24 XEL achievements.
Upgrade Burnhilde to the max.
Enter the Scorched Wasteland (without burning to crisp).
Upgrade your Clubber to the max.
Upgrade your ZapTrap to the max.
Upgrade your Sword to the max.
Solve the mystery of the Science Station.
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.
Smash the revolution.
Put an end to the madness.
Collect all Health Seeds.
Upgrade your Webshooter to the max.
Upgrade all Gadgets to the max.
Master all cooking recipies.
Parry for the first time.
Parry 100 times.
Collect all audiologs.
End your adventure without any upgrades (except THAT ONE for Chap).
Collect all Achievements.