Hello, this is probably gonna sound like a really weird thing to want to do with this engine, but bear with me here.
Is there support in UDK for making a 2d game using sprites? I assume that it's possible but maybe a lot more work than getting a 3d one working. If anyone knows if this is easily supported, I would very much appreciate the knowledge.
It is possible, but because Unreal Engine doesn't have an orthogonal viewport option in game (it does for the editor) you will still get perspective issues. Although mind you, I've never really looked into that too deeply so there may be a new orthogonal option now.
I would use XNA to make a 2d game. Granted it doesn't have a built-in map editor or things like that, but it will probably make your life easier than trying to turn a 3d into a 2d. Alternatively, you could go the shadow complex route and just only allow controls in 2d though the environment is 3d.
Okay, that pretty much confirms what I was assuming was the case. Thanks everyone.