RoboVM has been working pretty hard recently to cut the compile times down. I haven't used it in a year, but I read a blog post where Nick said he cut the compile times down by a ton. Plus he added incremental compiling recently as well, which should resolve your issue. :D
This was from me playing with it a week ago in the new robovm studio. It's still 30s with no code changes after you have built once, most of it being the robovm build part.
