- Fully functional undo/redo: you can now undo your mistakes -- whether it is the deletion of a ring group, a segment or even an entire special stage. The undo/redo are also smart, grouping many related actions.
- WYSIWYG drag/drop of selections.
- Rings and bombs can now be drawn in lines, loops, triangles and more in a click-and-drag manner, adding several rings and bombs in a WYSIWYG manner.
- Added a counter showing total rings, bombs and ring/bomb shadows. This can be used to keep them within limits, which would prevent a segment from ever ending.
- Grid-lock (toggled through toolbar button, defaults to on) constrains the possible angles for ring and bomb placement.
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Edit: You can also grab the source code on GitHub.