I loved H2O-- well, H2O and Route After and Another, specifically- I feel both titles are really necessary and that the ideal experience is in both games, not either one, but anyway- beyond the fact that I absolutely adore the art style (the use of lighting, above all) and the musc, the game combines all elements to create a near-flawless atmosphere. The setting; the village and its history were even reused in a certain later game, but no spoiling =P
Huh, right you are. Only three characters overlap, through- and no mention of a setting change.
I’ve never played it, just H2O by itself and Complete Story. Apparently you miss out on some ??? play moments with a certain card game and some other things.
It’s basically proto-Subarashiki Hibi. About every aspect is weaker, although Tsui no Sora adds a certain level of ambiguity to the ending which is interesting. I definitely recommend playing it first though- it doesn’t exactly spoil anything and it is interesting to compare the two stories.