The most important part of playing Ana is making sure you land your shots. Unlike her other healer peers, she's only able to consistently heal a teammate by shooting them with her Biotic Rifle. But, in a fast, real-time game like Overwatch, the reality is you will find it a struggle to get an incredibly high accuracy.
NickiiLovesMe posted this clip of some Ana gameplay. The player and their team are attempting to escort the payload on Hollywood. With the use of Ana's scope, the player attempts to heal the Nano Boosted Symmetra as she goes after the Orisa.
The player ends up missing the shot, but has another opportunity a second later as Symmetra makes her way back to the payload. And once again, Ana misses. Ana then turns towards the enemy D.Va, a hero that is pretty large, and uses her Sleep Dart.
It misses the intended target but instead hits the enemy Mercy, subsequently eliminating her. The Mercy faceplants into the ground, as the D.Va, now without a healer, gets her MEKA eliminated, too.
Even though every other shot didn't land, the most crucial one did -- and it wasn't even intentional. That is, without a doubt, amazing gameplay.
Clip courtesy of Reddit user NickiiLovesMe