I have a feeling that the UI would be one of the
easier parts of the sort of thing you're thinking of, rather than the hardest. There's already a perfectly usable interface in the game that's
already used to select from sex scenes, among other things. Make the upper rows of the menu options a list of characters/locations, the bottom row the 'Back' and 'Scroll Forwards/Backwards' options and then do sub-menus as needed. Not that complicated compared to the rest.
Much more difficult would be making the scenes actually function in a 'gallery' setting to begin with. First off, considering how pretty much
every scene in the game involves at least
some parser checks, you'd need to program in a system to tell the gallery what gamestate you want it to reflect (or else it would turn into garbage at every check) which isn't something the game is set up to account for; the existing Gallery is save-agnostic and just tracks what you've seen in
some state since the system was implemented. You'd need to code in a way to call up specific gamestates to run against all the parser checks and then you'd also need some way to tell the game 'you've seen this scene so it's unlocked now' for every scene you want to be able to go back to later. Also, the scenes in the game are not designed to be read in a vacuum, instead they're more like 'When W happens, then go to Scene X, optionally add Effect Y, then return control to the player in Location Z (or don't if it's a Bad End)'. For every scene you'd want to turn into something standalone you'd need a way to tell the game to only call up
this line to
that line and then drop the player back into a menu, instead of doing all the stuff that the game is
designed to do. All of which you'd need to add by hand. I suspect that this is one of those things where the programmers would take one look and say 'Well we
could go back to every scene in the game and do this but we'd really rather gargle battery acid, so just make some save files and see it yourself plz'.
