I had the opposite experience of the rest of the reviews. At first I was scared to break my mouse for trying to get the first upgrade by clicking, but then I found out that I could set up a little tower that brought me a lot of "shards". Then I spamed towers untill I got tons of shards, upgraded the mask a couple of times, and decided to upgrade one of the towers to max level. Then the UI stop responding and got stuck.
This is what I achieved!
I think the game needs to be polished in this aspects: UI, background sound (as it is an"active" iddle game), and, for me the most imporant part, progresive stat scaling. The second I learnt how to set up towers, no element could hit me ever again.
I may suggest something like locked areas that you need to unlock by paying shards, branched power-ups instead of linear ones, or the need to have a minimum number of towers to unlock a new max level for the artifacts. Maybe you could also pay to reorganize element areas in the field.
But I must admit something: not much tower defense games give you the oportunity to set up such a big number of turrets, and I enjoyed that. It is a good sensation to fill (almost) all nodes in the screen.
If you ever decide to continue this project, I would be glad to play it again!