Ooh, I hope to see more traps, I love those water things... So much fun to drop an item on to the pressure plate in there and then watch as somebody runs to get it...
I find black, green, and blue to be enjoyable however I like the simplicity of the red as it is like an open battlefield. Now, I myself would like to design a few arena's I have in mind. :3 They might not be added but it's better still to try.