Barrier Brews, v1.0

Inspired by games such as Overwatch and Apex Legends, I'm trying an alternate take on magical shields that I hope will make combat a little more interesting. 
I am also interested in developing barriers beyond this one spell - possibly using them in class features, magic items, and such. By playing around with shape, duration, mobility, and durability, I think there is some design space to be explored with this concept. Of course, it's still a pretty new idea, so there's still some refining to be done. 
Wall of Runes
2nd-level abjuration
Casting Time: 1 action
Range: 30 feet
Components: S, M (a quill or other writing implement)
Duration: 1 minute
Classes: Cleric, Druid, Wizard
A glowing wall of runes springs into being at a point that you specify. The wall is a barrier that is 20 feet long and 10 feet tall, but only 1 inch thick. The barrier has 20 hit points, and extends in a straight line centered on a point that you choose when casting this spell.
At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the barrier's hit points increase by 20 and its length increases by 10 feet for each slot level above 2nd. 
Barrier Rules
  • Barriers are manifestations of abjuration magic. They are translucent, and creatures can move through them freely. 
  • For the purpose of determining cover against attacks from hostile creatures, barriers are treated as solid objects. However, attacks from friendly creatures can pass through them freely. 
  • If an attack misses a creature that has partial cover from a barrier, that attack instead damages the barrier. An attack against a barrier itself will automatically hit, unless the result of the die roll was a natural 1, in which case it automatically misses. 
  • Barriers have fixed amounts of hit points, and will break once reduced to 0 hit points.
Artist: Zezhou Chen