I wouldn't have normally responded on this, but you said "any information is a massive improvement." While I can't speak to signup conversion rates, I can speak to an angle which you may not have thought of which, for me, adds a bit of trust to a name I haven't heard of, especially in a time of information/password leaks.
Security and familiarity. ...
The purpose of verifying email
If the user has entered the correct email ID or not
To eliminate the issues related to the forgotten password
There are two ways to solve the above issues.
Option 01: Make verifying email a mandatory process during sign up flow -> This makes the process more robust. But at the same time annoying for the users as well. ...
based on this process flow, Add to cart → Checkout → Enter Card Info → Charge → Download Item, I’d suggest putting the login sequence once the user clicks Add to cart (or save/ bookmark item if there’s any).
The reasons for doing so are
it allows you as an owner to track the sales funnel/ conversion on how the buyer decides to purchase the game (ie the time ...