Yasuo's wind wall blocks more than projectiles.

A projectile is defined as anything where it ha only the force of gravity acting upon it. In league of Legends all abilities travel at a set speed if connected to the champion and still counted as a projectile(ex: Bitzcrank's rocket arm). I can not govern pure magic and energy abilities since i do not know if physics apply.

Now I can be lenient with that for abilities like Caitlyn's ult or Ahri's q. Those would be considered projectiles if the target and the champion remained stationary (negating the force of the ability's need to track its target).

But what cant and never will be a projectile, but still blocked by his wall, are:

• Nami's ult. It is a wave. It physically has to be on the ground for the wave to form, thus giving it another force (normal force).
• Braum's ult. It is a fissure (literally meaning the ground opens).
• Lissandra's e. Moves along the ground, thus giving it another force (normal force).
• Kog'Maw's e. I'll give you that it initially comes from his mouth, but at some point that ball is rolling on the ground, thus giving it another force (normal force).
• Vel'koz's w. It is a rift. Its description clearly states it cuts through the ground.
• Malphite's q. It rolls on the ground, thus giving it another force (normal force).
• Zyra's e. Even in their cinematic it is shown coming out of the ground.
• Draven's ult. I have no idea. It is considered a projectile by game code, but it is cutting through the ground(look in the picture for the ability, or in game sprite. But the description says he hurls it which implies it is airborne. I will let you decide that one.