The upgrades explain nothing of what they actually are and as a person who just started playing, I don't even know if the upgrades will give me the items described or if will be for something unlocked later on.

Not being able to go back to previously completed levels shows that there is a fear of letting players farm to get stronger which in a genre as this is more of a negative for the game overall than any boon you could believe that decision could be.

The randomness of the dropping pickaxe is only fun when you are strong enough that you are not just dribbling on rocks hoping to break through (see that not being able to farm aspect already coming back)

Not sure if randomly generated but the second asteroid for me had a special condition to not be able to use the mouse clicker which then means not only were all of my upgrades that were put into that from the first asteroid wasted (and now I can't go and farm to upgrade the pickaxe ooh almost like a trend) but it also means that there could be possible situations where an asteroid has conditions against whatever else I could have built for and I wouldn't know until unlocking.  Thus making the player feel weak.