Speaking of the maximum number of games you include, I think that it is unwise to bundle them all together in one download. I think you should have a dedicated part of a server that hosts the mini game, and then the GUI connects to this area and then the user can download any game they want without having to have a massive filsize.

I don't know what you are writing the interface in, but personally I wouldn't use lite-c. I'd go for C#/C++.