3. I would personally make this game about mining cryptocurrencies, so for example, instead of starting with a goldmine and 1 worker, how about starting with 1 CPU-Miner (or a certain amount of hashpower), which you can upgrade in hashpower until you reach GPU-mining, and after upgrading that for a while you reach ASIC gen 1, and so on. In order to avoid confusion, you could create a made-up cryptocurrency like "BitMineCoin". Here is an example:
-)Player starts with 1 CPU-Miner and 10KH/s hashpower giving him 10 BitMineCoin per Captcha (or every 5 minutes). The basic price structure can remain the same, only now instead of upgrading the pickaxe, he is overclocking the cpu. And instead of buying further workers or gold ores, you can buy further PCs (later GPUs and ASICs) and f.e. solar panels. One can easily think of a replacement for the other resources as well, making coins like "BitMineScrypt" and "BitMineX13" instead of Coal and Iron.
I generally like the idea, but I think if you make it about cryptomining, more people would get an idea about the topic in general and it would just fit the theme perfectly.
If you like, you can contact me and we can discuss this further, happy to help.
That would be modernizing the theme, making it about computers/mining hardware instead of the actual mine with people to work in it theme, thus changing it's face and making something completely different, of which I do not approve, I like the theme as it has been delivered to us