Unity - 2D
https://blogs.unity3d.com/2020/12/22/the-road-to-2021-the-many-dimensions-of-the-2d-team/
2D Characters
RIG & ANIMATE 2D Characters in Unity 2019! (Tutorial)
https://www.youtube.com/watch?v=VwS0MRSRKKo
RIG AND ANIMATE 2D CHARACTERS in Unity 2018! (Tutorial)
https://www.youtube.com/watch?v=vPgS6RsLIjk
2D Animation (Unity Tutorial)!
https://www.youtube.com/watch?v=j0MGh4MVbGc
2D Animation in Unity (Tutorial)
https://www.youtube.com/watch?v=hkaysu1Z-N8
Unity 3d Tutorial Advanced 2d Character Controller inspired by Super Meat Boy
https://www.youtube.com/watch?v=tfcVRz0-sfk
Programming 2D Unity Games in C# - Free Online Course with Timestamps
https://www.youtube.com/watch?v=6zD14z6TWLs