Well, if You have over half the work done already, then coinpayoff might not be such a bad idea, but making it work for gold would rather reduce your loses (payouts) rather then gain You anything (You dont profit yourself from having gold). Also 1 person getting too much gold at once will increase his gold gained possibly too fast via upgrades (i believe ppl would cashout btc, while gold would be reinvested most likely) but that of course would depends on the amount of prizes.
Investment game sounds cool, but You need to start taking some fees for Yourself, i dont want that project to die, and You will have to stop giving away money at some point. passion is one thing, but Your costs will rise over time as more and more ppl come here and upgrade their mines.
About story telling i can make some stuff up today, havent checked your PM yet, forum writing is enough of a violation for me while at work ;p Just (if You havent yet) throw me some limitations - for example - if the stories are to be yes/no based, or multiple choice with different results, or yes/no with both answers having some effect, or some tree style deep rooted stories, or if they should be dependent on what upgrades you gained so far, with more advanced stories unlocking later ingame. I have no idea how much of programming it would take and what You can/ have time to make.
Lvl 11 pickaxe costs something around 3k gold. its only 2% but basing on myself as an example with 3 ores and 7 miners, 2% of 21 gold is 0,42 gold earned per minute. 3000 gold / 0,42 g/min = 7142 minutes which is equal to 5 days of straight mining. With my current chambers and equipment i need more or less 15 days to get it, i assume im mining for 8 hours per day. 2 weeks isnt that long, and with each additional miner/ore it comes way more efficient. Next lvl is 2x that, around 6k gold which also isnt much - remember that this game is really a long term to earn anything, so it will be returned. And those 15 days calculation assumes that i dont have previous 10 levels of pickaxe already giving me 20% bonus... While initial levels must be cheap to encourage ppl and give some incentive, i believe that around lvl 8 of that upgrade, 10 at the most the price should rise more than what it is at the moment. Beta or not beta, You are already paying out, so even as a temporary hotfix, increase the prices, at least of that upgrade a bit.
As an ad hoc fix for Your earnings if You ever need it without nerfing the game for players too much You can always lower chambers from 5 minutes to 4,5 or 4 minutes, more captchas solved - more gold saved.
And bank will kill you if someone deposits at once 1000k gold and noone steals it.
Investment game sounds cool, but You need to start taking some fees for Yourself, i dont want that project to die, and You will have to stop giving away money at some point. passion is one thing, but Your costs will rise over time as more and more ppl come here and upgrade their mines.
About story telling i can make some stuff up today, havent checked your PM yet, forum writing is enough of a violation for me while at work ;p Just (if You havent yet) throw me some limitations - for example - if the stories are to be yes/no based, or multiple choice with different results, or yes/no with both answers having some effect, or some tree style deep rooted stories, or if they should be dependent on what upgrades you gained so far, with more advanced stories unlocking later ingame. I have no idea how much of programming it would take and what You can/ have time to make.
Lvl 11 pickaxe costs something around 3k gold. its only 2% but basing on myself as an example with 3 ores and 7 miners, 2% of 21 gold is 0,42 gold earned per minute. 3000 gold / 0,42 g/min = 7142 minutes which is equal to 5 days of straight mining. With my current chambers and equipment i need more or less 15 days to get it, i assume im mining for 8 hours per day. 2 weeks isnt that long, and with each additional miner/ore it comes way more efficient. Next lvl is 2x that, around 6k gold which also isnt much - remember that this game is really a long term to earn anything, so it will be returned. And those 15 days calculation assumes that i dont have previous 10 levels of pickaxe already giving me 20% bonus... While initial levels must be cheap to encourage ppl and give some incentive, i believe that around lvl 8 of that upgrade, 10 at the most the price should rise more than what it is at the moment. Beta or not beta, You are already paying out, so even as a temporary hotfix, increase the prices, at least of that upgrade a bit.
As an ad hoc fix for Your earnings if You ever need it without nerfing the game for players too much You can always lower chambers from 5 minutes to 4,5 or 4 minutes, more captchas solved - more gold saved.
And bank will kill you if someone deposits at once 1000k gold and noone steals it.
Yes using Gold instead of Bitcoin will not earn me anything, but rather as you say, reduce losses. There's an old saying though, "what is not lost is earned". And besides, I'd have to think of legal consequences when I want this site to be long term. No sense in me getting a huge fine or going to jail (yes, in some cases you go to jail in my country from running a ponzi scheme xD) then. But reducing my losses is so far enough for me. I'll try and lay it out.
Currently, there is 1,796,842.467 Gold in circulation which is spread out on almost 3,000 users. Now, using the investment game with say 10% fee, and everyone playing, will make this amount 1,617,158.2203 instead, saving me 17,000 satoshi. The winner will of course receive a huge bonus, and be able to purchase upgrades faster, but the fact that losers will take longer to get upgrades would make up for it I suppose. I would rather have 1 far upgraded user who redeem say 100,000 satoshi daily, than having 20 users redeem 10,000 daily. Again, minimizing losses is basically the same as earning something. And besides, the fact that ponzi schemes are illegal makes it practically impossible to run the investment game for long, without someone who lost at some point reporting it, and me facing consequences from it.
Given the fact that Bitcoins are not really money in my country, but rather considered as goods, I might make the effort of investigating the legal situation of ponzi schemes with goods. Like, is it illegal to run a ponzi scheme with doorknobs, where people deliver 1 doorknob and receive 2 in turn from others?
I will message you again, clarifying the exact details of the events then. No worries, you can read it any time and take whatever time you need to write the stories. There is not at all any hurry for this
I have written down, that I need to look at prices for pickaxe then. I will not touch the chamber yet though - the maximum amount of time between mining I believe is 3-4 hours so far. I think that's a good starting point, forcing people to mine 6-8 times a day in the end.
Although, I do already have the working mechanics for the investment game, so it wouldn't be too difficult to integrate. I will have to consider it some more though - but I am pretty firm on the fact that it will be in-game resources and not BTC used for "deposits". 
You would just have to really CLEARLY state all the rules, and You would skip fees if the btc were to be send to the users accounts instead of straight to the wallets. And ofc You would have to switch to much lower fees and amounts, like 5-10 k satoshis instead of 100-500 k. That way, You would already have a pool of users. The only thing to worry about would be informing at all steps that it is gambling in which some ppl really lose and it cant be avoided.
