I have quite some Feedback for the newest update. Really like the changes so far.
• I like the new UI, looks cleaner. Just took me a moment to see that you can scroll down in the shop.
• Glad you implemented the challenges that quickly, that's nice
• I like the new used/practised/etc mechanic, feels nice.
• I really like that you can now choose between boosters at the shop and sort of select the rarity.
I do have one issue still with the balancing and one wish for future versions.
Balancing: It still feels weird how the prices scale. I get that you don't want to make it too easy for players, that they just buy cards in bulk as they get stronger. But it feels a bit punishing at least for me. If that's what you're aiming for that's fine of course, but let me explain. Of course you want the best card packs always, but you can't afford the Reliquary Pack right away. So you start buying cheap packs but with doing that, you make it even harder to buy Reliquary Packs in the future. So you have to choose between getting less good cards early and being punished in the later run or waiting (which can be a bit boring, although it's an idle game, I get it). The second thing with this is that the prices don't scale when you buy individual named cards and not booster packs. But the prices of the individual cards DO scale with me buying boosters. So for me, it feels the smartest thing would be to buy all the named cards, wait 15 minutes, buy them again and so on without ever buying boosters or only rarely. Again, I feel punished for buying boosters.
Now my suggestion.
Make booster tiers scale seperately. If I buy a starter pack, only starter packs get more expensive and if I buy reliquary packs only reliquary packs get more expensive. Also make it so named cards don't scale at all, but make them way more expensive to get them at first. Like a common card 500, uncommon 2k, rare 5k, legendary 20k or something like that. As you only get them every 15 minutes anyway I don't feel like that would be too OP.
Wish: I wish for future versions to have some unique card rewards. You could make it so in the challenges if you manage to beat the 3rd and 6th challenge tier, of say nature, you get unique nature cards you cannot buy.
Or you could make some unique card challenges, like earn xyz/minute with a "Gold Coin" on the board or have a "The Void" with at least x amount of Tags. You could then get a reward for these challenges.