Probably the quickest I've ever gone from demo to purchase.
As Ys tends to go, it's a ballbuster, but a damn fun one. Combat is surprisingly flexible for its simplicity. The set piece boss fights are creative, complex, and completely unforgiving, but for the most part tuned very well -- a player who's practiced up can take them down reliably and feel like a total badass in the process. Experience gain is tuned to scale based on the level difference between you and your opponent, so you catch up very quickly when underleveled but can always crank out an extra level for an edge against something.
There are exceptions, of course. Kishgal is capable of randomly screwing you depending on which moves he does in succession, and a couple bosses (Gelaldy, Pictimos) are long and tedious enough to stop feeling fun after the first half of their HP bar. The latter third of the game is extremely melee-unfriendly, and poor Yunica is largely reduced to spamming one special attack.