in the quests panel there's a transparent text in the bottom left corner that tells you what to do next. What does it say?
sorry about the second issue mentioned, i'd played through the game by checking up on everyone, didn't notice the objective text. for the record, this game was $8 well spent
when i first downloaded and played the game. the audio had no issues. i can't for the life of me think of what i may have done to set this issue off, but i've noticed that save data persists even after trashing the game's folder. if you could please let me know where in a PC's memory the game's latent files would be stored, that'd be all i'd need, since theoretically, fixing this issue would be as simple as deleting those files and forcing the game to reestablish them.
also if it helps. for some reason the inflation sound effect from the water drinking minigame still works even though all sfx are at 0.