Wait.Since you're a web developer.What you need a sponsor for ? You can program the game like a blue print but basic working model and then you could present it to some investors ? You most likely won't get any investors since you just have a idea and investors usually want a working model, a basic one to see its potential.Since you're a developer I suggest start working on the basic model using free services.
What I'm afraid of is that others will get this idea stolen. Well, maybe I'll start a working model and present it to interested investors.