I agree with other reviewers that at the current state it's pretty basic and definitely has potential.
Here are my 2 power crystals:
- UI for choosing element upgrades is confusing. I think, it would be better to either list all available combinations (taking available materials) or something like "click first element -> click second element -> confirm/abort"
- Music - I like the current choice, but would love to see few less intense tracks to be dropped in for variety.