Suggestions: Unlock new ores using jems and another new upgrade set, they could be shown on a grid or something. Add levels to the earlier ores to stretch the unique mining options. Who wouldn't give an extra star for poo lvl 3?
Quality should be capped at 300%, getting lucky with 762% quality is too big a jump in dps. I pass most rock types in less than a minute with clicking, less time than you spent drawing them probably. Usually 3-4 can easily be picked off after a weapon upgrade which generally at least doubles the power of the last one.
Great graphics, unfortunately they forgot to implement the fun. About the time you get your 2nd dungeon you run out of quests that can be easily obtained and they give a few quests to get you to spend coins that might save you a lot of grief later, like the 25 map square upgrade. I can't imagine too many people tolerating the game up to level 20 without spending. Also, there's nothing fun about surveying multiple mountains one dungeon at a time, but it's very important to get a good resource mix in your second dungeon.
I like the game, only made it to level 5 so far. I find the enemy damage to be rather random, sometimes I'm taking no damage, sometimes I'm loosing 10% of my health per hit. The shield is a little confusing, is it only blocking damage while the power circle is filling? I like the simplicity of controls, but I find it hard to see what's happening when there are several enemies near me. Despite my personal quibbles, I'm going 5/5 for the fact that you are actively enhancing the game.