>>718208176
Astlibra's a much better (and longer) experience, but it also had the benefit of having something like a decade-plus long development time while BS1 had something like 9 months total spent on it and a runtime of 10+ hours. Both games extensively use premade assets and music, sometimes even the same ones.
BS1 overall is what I'd consider a 6/10 game with some interesting endings and attention to detail bringing up the score, while I'd consider Astlibra a 9/10. BS2 is the entry that most people here regard as good (I'd call it a lopsided 8/10 game, gameplay still isn't quite there but if you're a lorefag this shit will hook your ass hard) and is a direct sequel to the events of BS1, so you can't really skip to it without missing some important context.