"If a game costs $10 to make in China"

It doesn't though. It costs a certain amount of Yuan. About 70CNY

Therefore to make the numbers add up now they need $5 to buy 70CNY

Which means to make China a viable source, the exchange rate needs to go from 1:7 to 1:14.

Those Chinese Sovereign wealth funds need to be more generous with their CNY if they want to keep the manufacturing.

The USD is currently sharply devaluing, and Trump appears to be quite keen on this idea. China attempting to keep up would cause all sorts of issues.