@extramana, extra almost doesnt have ero-scenes, just 1 for each heroine, unlimited is not back story, is part of the plot itself for alternative because alternative is the sequel to unlimited.
playing ame no marginal so far it's good, I don't like the fact that some of the songs have really low quality -.- ( is like listening a 56kbps mp3 song) and they even reused some from narcissu...