Yeah I agree the last track is very good, definitely one of the album's highlights. The only thing different with it is the lack of a tremelo picked electric guitar.
Also, if you have read any interviews with Neige you would know he is a big fan of Yann Tiersen's "Rue Des Cascades" and to me, this last track seems to be him trying to replicate that sort of sound in his own Neige-styled way.
I just finished one full listen through and here are some of my initial thoughts. The sound is definitely heavily inspired by shoegaze but seems to be more 'refined' due to the frequent use of acoustic guitars towards the crescendos of the songs. I also detect traces of the whole "post" sound through the heavy use of layering, especially as the songs climax. I remember reading in an interview with Neige about Alcest and he stated his goal was to conjure extreme nostalgia with this project. I think he has largely succeeded here. The cover art even seems to recall the innocent bliss of a carefree childhood in the dawn of a new Spring season.
Moreover, the album is extremely consistent with its sound. Each track feeds into the next near perfectly allowing the mood of the songs to be fully enjoyed with little obstruction. In other words, the flow of the album is pretty much spot on. Considering how strong the consistency of the album is, one would assume that a necessary lack of distinctness between the tracks would follow. This is not so. In fact, even though Neige makes use of the same 'bag of tracks' (i.e. picked acoustic guitars, tremelo picked electric guitars, dense layers of sound, relaxing, almost spacey vocals) he is able to twist and turn these ingredients, mainly through varying approaches to song structure, so that each song has its own identity while still appealing to the overall motifs of the album more generally.
I definitely need to listen to this more, but my first impressions are very good.