Will admit I only gave this game a few minutes. UI is nice, very clean and sharp. Otherwise I felt like I was playing Cookie Clicker, but with rocks...and less to do.
Different players will have different things they're looking for from a game, personally I like some hard limits to reach for, like unique upgrades (e.g. there's a limited number of times you can buy something).
It's also set in a quarry, so might be nice to have a village/town/city (prestige levels?) that you work towards?
Maybe don't have "all" of the upgrades visible at once, but locked behind progressive research...given your icon is a stick then maybe have some kind of civilisation style research tree that unlocks new upgrades, functions, quarry types ETC. Although thinking about it....breaking rocks with a pointy stick then purchasing a "drone" to help you automate stuff seems a bit.....odd? That somewhat comes back to the Village/research tree idea though.
Perhaps you break rocks, get sand and stones, build a hut then hire a Neanderthal to help break rocks, 2nd hut is more expensive and the 2nd Neanderthal helps find more rocks (increases number of rocks on screen?), 3rd hut more expensive again, 3rd Neanderthal helps find new rocks (clay) opens up new buildings for the village...and so on. Note I'm not suggesting a Kittens type thing here where you can keep building things as long as you have the resources, my thought here is that each building has a fixed purpose and limit on how many can be built and that would be part of prestige...so a Village can only have 3 huts, a town might have 5 with huts 4 and 5 providing additional bonuses/features. You could add an additional prestige layer of "era"....So Era 0 might be fully manual rock gathering, Era 1 would be with Chimps, Era 2 Neanderthals, Era 3 Homo Sapiens each representing a full reset (with progression boost and additional levels for buildings).
Or ignore all that and do what you want to do :D