Finished a playthrough on normal. TL;DR: Game is good, if you like Ace Combat you will like this.
PW gets a lot of things right. The flight model is tight and good, plane selection and weapon variety are good (and, unlike some Ace Combats, attackers do have their place here), and PW's implementation of post-stall maneuvers turns it from a somewhat useless gimmick in AC7 to something actually useful. The story is straightforward and doesn't carry the same baggage of repeated restarts and rewrites that AC7's did, and PW even manages to add in an optional character for those occasions when you pilot a 2-seater plane. This would be a good game if a "proper" studio released it; that it's the work of just a few people makes it all the more remarkable.
That being said, I do have some criticisms. There is a noticeable lack of polish in some features: The UI flow going from a briefing to launching the mission is a bit clunky, the in-game codex is very hard to read, some of the visual effects are somewhat overwhelming. The writing needs some editing for flow and pacing; some sentences in here do not actually scan, and there are notable discrepancies between the spoken text and the subtitles. Missions tend to go long, there are a lot of targets to deal with and no in-mission checkpoints.
But these are small quibbles in the grand scheme of things: This is still a very good Ace Combat-alike, and I highly recommend it.
