I haven't seen far enough into the game to know what else would need to be looked at other than the intro feeling kind of rushed? idk it felt weird when they just accepted the main character as king, that might be something that they talk about as the game progresses and events with those specific characters happen. but yeah, the main problem is just that things aren't explained.
For sound effects though I think it's mostly menu sound effects that were extremely quiet and a lot of other general sound effects like the ones in combat are too loud. This is with all the sound settings at the same level at like 20% or whatever this version of rpgmaker has as it's lowest non-mute setting.
immediate edit: is there a way in game to see all currently available quests? if not... then that, please. That might be annoying to make though and would probably involve a fuckton of unique flags to set depending on what stage of the game you're on and what quests you've completed unless you do it in a broader way somehow.
Yeah, I agree with you about the pace of the intro, like it is too fast. But I understand why the arthor do it, nowaday, much of H-game player does not care much about the story anymore, they want to try out the gameplay feature right away. But I feel like it is best if there is some features to further emphasize the uncertain of the Central politics at that point, like we can hear gossip of people, regardless of servants, royal officers, nobles or ordinary citizen of Central about Ryen when he was lead to Aldyn to be the next king, like they have known or show some suspicions about Ryen's indentity, but some are just lost hope in the previous kings of Central already, or don't care about royal linage anymore and just want to see if the newly king can make a difference in reforming Central which is in shit state. Base on the rough roadmap of the game the arthor made, I hope that when in the time the new that Ryen is not in the linage of Central's monarch, base on the status of the kingdom (like happiness, security, etc. what we have done so far for the country), people shall have different opinions about Ryen. If we do all the good thing, people shall praise and endorse the new dynasty without conditions, or else maybe some revolt battle, or even a mass coup (that shall be fun to see). In the future, when the main story is done, it is best that the intro have a re-vamp to improve the story though.