Version 1.4.0 has been released and with it some bug fixes, 4 new unusual levels ('MURICA, Killer Clown, Caution, Checkerboard), and an overhauled level browser that is hopefully more to everyone's satisfaction.
The next update I'm going to be focusing on making a level designer. It's about time that such a feature gets implemented, but it may take some time. I want to give players plenty of options as well as enable workshop support.
As always, feedback and suggestions are encouraged and let it be known if there are any technical issues overlooked!