dnd 5th – Is this homebrew wind wave spell balanced?

Nicely close!

First of all, I love this spell. It's a nice combination of damage, battlefield control and defense. It is also mechanically similar to two existing first-level spells: A wave of thunder and Burning hands. And in most cases, their power and efficiency are similar.

The only problem with which I see a potential problem is the ability to knock out multiple enemies. If you remove this and many of your allies have tricks in front of your enemies, you guarantee an advantage over melee attacks. It's a bit powerful for a first-level spell that also deals damage, especially if one takes into account that some very common low-level foes that band together (eg, goblins, kobolds) tend to have catastrophic strength scores. Add this to the fact that neither A wave of thunder or Burning hands create similar status effects, and you have a spell that has a bit too much "bang for your money".

I would suggest that the "subject" element be given as part of the upward conversion. Specifically, if this spell is cast with a 3rd level location or higher, creatures that fail the save throw are also prone to shock (in addition to increased damage). At this point, I think this spell will be ready!