Hi, I'd like to work on a game, but for rapidly prototyping it, I'd like to keep it as simple as possible, so I'd do everything in top-down 2D in GDI+ and WinForms (hey, I like them!), so I can concentrate on the logic and architecture of the game itself.

I thinking about having the whole game logic (server) in one assembly, where the WinForms app would be a client to that game, and if/when the time is right, I'd write a 3D client.

I am tempted to use XNA, but I haven't really looked into it, so I don't know if it won't take too much time getting up to speed - I really don't want to spent much time doing other stuff than the game logic, at least while I have the inspiration. But I wouldn't have to abandon everything and transfer to new platform when transitioning from 2D to 3D.

Another idea is just to get over it and learn XNA/Unity/SDL/something at least to that level so I can make the same 2D version as I could in GDI+, and I won't have to worry about switching frameworks anymore.

Let's just say that the game is the kind where you watch a dude from behind, you run around the gameworld and interact with objects. So the bird's eye perspective could be doable for now.

Thanks.