There are two types of artifacts in the game, ancient artifacts and class artifacts. If you are still trying to get the 5 hidden achievements tied to the 4 ancient artifacts or are looking for any of the 13 class artifacts this guide will describe how you can get all of them at any point in the game. Be prepared for a long grind.
4 Ancient Artifacts – Space Explorer and other Hidden Achievements
Have a Romancer in your party and equip the Player Books + Chicken wings in the Metashop. Go to Tanton (the starter planet) and fight two battles of 6 elite enemies and that should guarantee a chest spawn on the map. Hope to your respective deity that it’s an artifact and rinse and repeat.
Your player level doesn’t matter so bring any party that can deal with these fights as fast as possible. I recommend a Savage with lots of initiative so that you can AOE with Global Rage all 6 enemies. And put something on in the background cause you’re gonna be grinding for hours.
Afterwards for the remaining 4 hidden achievements (Shaolin Blast, God Stomp, Blast of the North Star, and Longest Shot) use the artifacts to upgrade their respective skills (Charged Attack, Forced Slowdown, Piercing Attack, and Multi Shot) and use them once.
13 Class Artifacts
Equip The Romancer to your party and Player Books + Chicken Wings from the Metashop again. If you can’t find any more fights because your team level is too high (mine was level 40) you can reset your party members’ upgrades and remove party members to bring the difficulty back up. My setup was to go to earth with only two characters, a Savage for AOE and a Medtech for healing and just grinding 4-6 of the elite ronin until the artifacts dropped. The class artifacts have a much higher drop rate than the ancient artifacts so you’ll have a much quicker time getting all 13 but you can get duplicates.