Pretty strange. OK very strange. I can't help but think Oldman's performance was inspired by the the guy in Twisted Nerve. By half way you don't know whether what you're seeing is all real. Maybe that's the point.
I didn't think Lloyd's character was all that interesting, even with the quirks. Oldman's characters was pretty much a trapped mental state. The mother provided the mystery, and that was the best part, until a point.
I think the downfall is that it didn't really develop well. Lots of sce es that seem empty. One example, there is a scene with Lloyd doing a stage talk and it just goes on. That's cut with Oldman messing about just to be mad. Rarely scenes are brilliant and give you development whilst giving more mystery, like the scene in the cafe. But overall the plot development was slow and didn't go anywhere new. If only there was an incredible atmosphere to fill the void. It would have helped a bit. It's gets slower as it goes on and by half way we kind of get the movie.