Todo
====
- [ ] new game menu
	- [ ] save/load preferences
	- [ ] load custom image
	- [ ] flip panel for more options
- [o] piece
	- [X] rounded corners
	- [ ] thickness
- [ ] highlight hints
- [ ] art generator
- [ ] properly align widgets
- [ ] winning animation
	- [ ] reflection glare? 
- [ ] save/load current game

Resources
---------
- https://github.com/GDquest/godot-platformer-2d
- https://tomodachi.fandom.com/wiki/Slide_Puzzle

Image generation
----------------
- https://en.wikipedia.org/wiki/Droste_effect

Image collections
-----------------
- https://search.creativecommons.org/collections/rawpixel
- https://www.rawpixel.com/category/53/public-domain
- https://www.rawpixel.com/category/83/rawpixelcollection
- https://www.si.edu/collections

Color palette: https://lospec.com/palette-list/slso8

Inspiration
-----------
- https://playzhed.com
- https://managore.itch.io/adrena-line
- https://petputt.com/