I'll just get my negative stuff out of the way first because its really just more of the same stuff. This episode is horribly rushed and is cutting out a lot of content from early alka that I quite liked in the VN. They're keeping most of the important stuff, but it's losing a lot of the soul. Alka is great because it's a slow-burn story that slowly builds itself up with a lot of SoL while slowly mixing in the mystery until it reaches a breaking point. Cutting out a lot of these really fun SoL interactions makes Alka so much less enjoyable to me, pretty much everything not involving the main 3 has been cut out so far which is awful. One of my favorite things about SP is the sense of community on the island, and diminishing the involvement of the rest of the cast outside Shiroha, Hairi, and Umi just lessens the experience so much. If they keep going down this path I struggle to see a world where the rest of this adaptation can be all that serviceable.
On the good side though, I absolutely love the new OP & ED! It's the first time I felt a Key true route has had an ED that fits the tone of the true route outside of Rewrite (I love the LB and Clannad true route EDs, but tonally they don't really fit those routes much), and the OP being a big more toned down but more emotional is a fantastic choice and it fits Alka very well.
Despite all that they cut out, most of what they did adapt was done pretty well. The paper airplane scene was adorable in the VN and was still just as silly and cute as it was there, I loved actually seeing the Quetzalcoatl scene adapted was funny as hell, scenes like that where seeing it get animated gives it new life are one of the only reasons I'm still watching this adaptation.
There was one scene where I feel like they showed a bit too much for this early on in the route, but this anime hasn't cared about massively spoiling the mystery at all up until now so I guess I shouldn't be surprised that they haven't changed their tune on that. Nowhere near as bad as prior routes have been about spoiling stuff early though, so I guess that's a positive. It's just hard to be invested when so much stuff I fondly remember from the VN is either cut out entirely or skimmed over very briefly, such as the radio calisthenics. That was a whole recurring event in the VN for a lot of early Alka, and all it looks like its gonna get in the anime is a 5 second pan over an image of it happening. Just really sad to see one of my favorite things ever made not get the justice it deserves