Sorry Ammo, the video is blocked in Germany.
Atlau most of the video is variations on a snap roll where you stall one wing. Even the half roll is a snap roll. You pull the stick back and to one side and push the opposite rudder pedal. For an inverted snap roll you push the stick instead of pull. Entry speed, flaps, and climb angle will change the result as well as how long you hold the stick and pedals and when you reverse or neutralize your controls. If you want to play with it a good start is a P-47 or F4U at 150-200 mph with 2 or 3 notches flaps going straight up.