Stable & 3.0 Versions have a fun problem with the character menu jittering when your mouse cursor is in the margin. The 'cartoon expand' effect from mouse-over will loop, making navigating the menu by clicking and dragging the bar impossible. Other brief UI critiques include the transient nature of most of the menus when you are clicking on character/asset items on screen, which can layer over/under the default menu options in certain display situations. The UI is cute but at times borderline non-functional when these conflicts crop up, which for me is quite frustrating.
A traditional fixed menu option would be optimal to add as a feature sometime, as it would assist people with interface difficulties in navigating the software and avoid UI conflicts. Thanks!