Artifacts?

[emilyoisasquid]

I've had artifacts for a while now, to the point I have 100's of unopened chests. I have been unable to "level" up the artifacts that I have, even with the correct amount of materials. Is there anyone else having this problem. How do you make the most of artifacts?

[Kohlenstoff]

Keeping unopened Chests slows down your game!
https://steamcommunity.com/app/1530340/discussions/0/3043859512559685893/
Having hundreds of chests can cost you more than 30 % of game speed!

Artifacts have a upgrade limit. Gold and silver max out at level 5 and bronze at level 10. I had no problem upgrading these to this limit.