One thing that would make us very happy would be to have the option to include a lengthy collapsible guide/instruction to each of our games. The current Game Description field is perfect for basic description of the game, but including the game guide on there makes for a less than elegant page where all the content/purchase/forum is moved at the bottom.

Thanks :)

Agreed

Where do you think would be a good place to put this. Do you want a links to separate pages within your main project page? Or purely a collapsible section on the main page?  HTML5 has a details tag that might be able to be used: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/details

I could whitelist that tag for our HTML sanitizer. It's not exactly the best looking though, so some CSS may be needed to clean it up.

It could be simply a collapsible part of the page, 

but the best situation would be a button that links to its own page, something accessible through the client as well. 

To Edit

I was thinking a box just underneath the description. Would this feature were to become very popular, maybe its own tab, but until then, I don't think it's necessary.