Nice little timewaster. One thing that bothers me greatly though is the fact that sometimes, advertising on National TV gives you 10,000,001 ad targets. This disturbs my gamer OCD on a painful level :'D
There's really no reason to have to click achievements to unlock their corresponding picture. Why not make this happen automatically upon reaching the required milestone? Also, like others said, Toughness can't keep up with the rest of the upgrades. Why not change Spites effect to a multiplicative 5% toughness increase? I think that would help out a little with relatively high cost without making it too broken.
Considering the price of Diamond Upgrades, I'd recommend either increasing the Diamond gain from hitting rocks to 4 or 5 OR increase the drop chance when hitting the rocks and not increasing the amount. I have an upgrade sitting here that costs me over 5K diamonds, and it's not even the last one, and getting that would probably cost me an unreasonable amount of time. Especially when considering that the Diamond upgrades are basically a necessity to get anywhere and with progressing pickaxe upgrades you get less hits on rocks and as such less diamonds per rock.
Hi Robolon! Thank you for taking the time to write out such detailed feedback on our diamond progression. We totally understand where you are coming from - blacksmith upgrades almost don't feel worth it when it changes the amount of diamonds you could get from rocks. We have taken note on all of your feedback and are working towards some balancing changes that will help scale this system into the late game.
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Hahaha the extra 1 is meant to annoy you and make you question what is that exactly