Seems like hitboxes are a pixel too high – if they pass adjacent to the wings, it counts as damage, but if you’re gonna go minimalistic, you’d definitely want those details to read right. I’m reminded of an anecdote about how near hits are even counted as misses in Super Hexagon, because it just feels better for hard games to not beat the player by means of ambiguity.
And yeah while the urge to make everything an upgrade is understandable, it’s my feeling that the ship starts too slow to make an avoidance style fully possible, so you get into the habit early of just staying in one place and getting better at shield-timing.
I hope my feedback comes across positively; could be a nice elegantly simple type of game with a few such tweaks!