I’m not sure if everyone knew this so I thought it might be important.
The Alice series are Cero D rated games. I’ve taken a screenshot from wikipedia to show what that entails. (Source: https://en.wikipedia.org/wiki/Computer_Entertainment_Rating_Organization)
Something I should add is that in games with sexual themes this rating is what is used when the game is just short of containing porn. On top of that QuinRose is known for pushing their limits.
The Alice series has always been for a mature audience (Though I’m sure some fans are kids and if they feel that they are ready then that’s their choice). It contains adult content.