Walkthrough videos
Here is a series of short videos which will get you started building 2D games in Unity.
- Unity Hub
- starting a new project
 
- Adding objects and making them interact - adding objects
- sprites
- Rigidbody2D
- colliders
 
- User input; complex objects, and lots of them - responding to user input
- compound objects
- prefabs
- constraints
 
- tagging objects
- collisions