Game is wonky, good bit of glitches, but damn those CG and animation make up for it. Sucks there isn't an easy gallery.
Careful with ctrl-skipping or else you may get stuck. And occasionally if you reset from checkpoint your HUD might disappear or you'll get a black screen. Jump attacks are overpowered so abuse it if having trouble.
Story is basically Vivi and friends head to this island to investigate the pretty aurora but gets separated suddenly. Once they reunite they find out the major port for the island has a gang harassing and kidnapping women so Vivi and friends decide to take them down. Why are they kidnapping villagers? Turns out the aurora are not just pretty lights but magic. Turns out descendants of the islands came from Witches and originally there were a whole bunch of them. Flash forward and one magic war later, the adult Witches sacrificed themselves to seal away the magic but their children can still use them. With the aurora, it activated Vivi's and other's latent powers and also affected the monsters around the island. Vivi and friends then team up with the women who can use magic to take down the gang leader and save the island woo~
All this came from auto-translate so I'm a little unsure on some stuff, like the story with the bandaged girl. The final boss was pretty neat.
Here is the save, place it in ヴィヴィと魔法の島_Data -> Save. This will have all the areas unlocked. If the gallery isn't unlocked type "Vivi" it'll unlock whats left. For animations you have to go into the stage and lose to see it.