It is ready for release, and it’s excellent for learning purposes.
You can try out the game:
How to play?
On mobile : Tap on the screen to shoot the player down.
On desktop/web : Click on the screen to shoot the player down.
Your goal is to hit the obstacles which have the same color as the
player. However, if you hit an obstacle which has different color than
the player, then you lose.
Unity 2018.2.13 or higher
Documentation contains everything.