itch.io

A crosshair would be really easy to add.
A canvas and a circle sprite at the center of the screen will do.

The rest are things you will have to learn as a game developer because they are things that can improve the experience of a game.

They may seem hard to learn at first but once you get the basics you can quickly master them.

Amazing Let me know hot it goes. I am also a new indie and learning how to make games myself the video was very inspiring!