If the loading screen is artificially long, cut it down to only what is necessary.
The amount of floating text is too much. My eyes are drawn to too many places to obtain rapid information the game presents, like boosts, quest progressions and damage done to the rocks. There seems to be an area to the lower-left that some text appears, this is a good location to consolidate all the gameplay text to. I often missed the mining boost popups as it blended in with other UI clutter.
The UI is very bright and blank, playing at night it was difficult at times to look at when a large white window was occupying most of the screen. I would find a good color pallete from your existing UI assets and use a tool like coolors to find a good neutral background color to replace the white with.
My framerate drops severely when looking towards the “Desert Door” barrier. There appears to be a giant area behind it I’ve not unlocked. If the user doesn’t have access to that area, consider de-rendering everything in their on their client so my performance isn’t negatively affected by rendering details in a location I can’t see.
To improve the flow of the players’ movements, consider speeding up the player when they are walking on paths. It will influence the player to not take direct, slow paths between rocks, separating the work from the travel time between rocks.
The UI for equipping pickaxes was unintuitive, I should be able to double-click a shovel and it equips it. Took me a moment of trial and error to figure out the blue icon needed to be toggled, then I select the pickaxe I want to equip. Still not sure what the star button is for.
“Boosters” tab should be under “Premium Shop” considering they’re also gamepasses, unless there is a way to obtain boosters without microtransactions that I’m unaware of.
The UI assets are beautiful, but they occupy much of the screen where it isn’t necessary. The bottom bar of icons often overlaps the mining boost popups.
The map is surrounded by invisible walls, but the cliffs also have collisions enabled. It’s entertaining to see how far you can climb some locations, but for performance I would disable collisions on the visual cliffs and rely only on the invisible barriers.
The transactions aren’t very exciting, like when a pickaxe is unboxed, or you open a present. Good sound design would really amplify the reward factor of obtaining something new. I would add a celebratory chime or sound effect to make the player really feel excited they just got something new and shiny.
Speaking of sound design, the music is sleepy, and the interactions are either silent or very quiet. I would like to hear some satisfying sounds as I crush tougher rocks with better equipment. The world feels very bright and energetic, yet the sound design is so mellow.
*Forgot to add a positive note:
The polish is really nice, it’s very apparent it’s a passionate project and doesn’t come off as the same played-out simulator title to me. You have great talent and I’ll be following the game to see where it goes, I think it’s a winner.