It's a hentai Alice in Wonderland type adventure in which our three heroines are sucked into a series of alternate fantasies. You chose from between one of eight scenarios, and play through. Artwork is nice, however, there is very little interactivity. If you ever wanted to see a girl raped by a giant mushroom, this is your game.
I believe this is the game that (Likely many early h-games) inspired the ecchi anime by the same name.