Hello ! Excellent and great work and great work!
however, there are several suggestions:
1. Add buttons to select animation (or hints in the form of text)
2. When exporting, the image is not saved unless you add an extension, for example - 'Image' - does not work, 'image.png' - works
3. Also, when exporting, sometimes one file is created with all animations of the type 'skeleton_universal.png', and sometimes several separate ones of the type 'skeleton_cast.png', 'skeleton_hurt.png', 'skeleton_idle.png'. I can't catch the dependence
4. Running animation (on available resources) would be an excellent addition