It would be really cool if there was a switch you could flip so that the game might randomly select ex-US market histories such as Japan, Australia, South Korea, Turkey, the UK, Europe, Brazil, Argentina, South Africa, Egypt, an all world index, etc.
When playing the game in the historical US market, most of us know there is a dominant strategy - B&H, but I wonder if that rule holds everywhere? E.g. Argentina or Japan?
People arguing "this time is different" because of demographic change, tech, climate change, the rise of China, etc. would say there are reasons the historical US economy will not resemble the past, and this would diversify things a bit.
2nd observation: do you realize you have about 60% of the pieces in place you would need to create an internet monte carlo strategy simulator? E.g. A tool to answer questions like what if I set a rule to sell when markets drop 5% and buy 7 days later, and ran that rule through 10,000 sample periods? Investors, brokers, and researchers would love such a tool. They currently use Excel!