It's because a VN should be about reading the text and making choiches that happen to put the player into one of several branches.I dunno what's the 'ick' with free roams some people seem to have. Is it because you just want to masturbate so non-lewd parts of the game in general bore you? Is it because you spam-click to progress as fast as possible and then can't figure out what to do in these free roams? Is it because you don't like parties and would rather sit cooped up in Maya's dorm instead and watch some movie? Just curious, not trying to judge.
And once one playthrough is finished, most of the players want to explore other branches too.
Ren'Py is the perfect engine for VN: it is precisely designed to let you skip already seen text in order to play different branches focusing only on new contents.
Exploring a big mansion, could be fun the first time. From the second onward is just a bunch of forced clicks chore. Boring.
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Besides in a VN which is this big, after years my memory just need a refreshment.
I would like to be able to spend my time just to read the plot to refresh my memory, and it could be done much faster if I wasn't forced to find the fucking kegs every fucking single time!
The kegs are just an example, of course.
This VN calls for being played multiple times and free roams are fun (or may be fun) just the first time.
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Plus the fact that the order in which you accomplish the various quest could result in missing some content, is just obnoxious.