1st welcome to the community, I hope you enjoy your stay 
2nd , no . There isn’t a place where you can ‘‘Suggest’’ your idea and others make it for you . This place has reader and writers , and many do try to make their own .
You can of course, post your ideas in the Interest Check here : Interest Check Thread
And make sure to clarify that you are offering your idea if anyone is interested . Just be nice and don’t pester anyone to use them . Writing is a skill that take alot of time , and when you add coding…it become harder .
Choiceofgames is a business first and foremost . So its up to them to decide what can be free or not . I don’t know why Choice of the dragon was free , maybe it was the author decision, or the compagny . But above all, they are here to sell stories games .