I've followed the first ~50 or so videos mainly because I'm interested in 2D game design and game physics at the basic levels (writing engines and physics).
Commenting to ask if anyone has additional resources / streams / guides on those topics they can recommend.
I'd recommend making at least three games and shipping them on existing engines before trying to write your own. That's the best way to figure out what is and isn't a must-have feature.
Beyond that, if you're interested in physics look up everything Erin Catto has written about the design and implementation of Box2d.
Commenting to ask if anyone has additional resources / streams / guides on those topics they can recommend.