Regarding the beeps: You made a valid point and we’d be alright with using different beeps but it has to stay consistent per character. My recommendation as well is that they are all of the same kind of sound wave (triangle, sine, etc) and the only difference between them is pitch.
Animation: Extensive animation would probably be something that reasonably requires like, more than 5 frames or so to work. You can easily get a blinking animation with 3 frames, mouth to look fine with 2. Please take into account the spirit of the jam: to make a VN in the most simple and crunch-free way.
We consider the Splashscreen to be GUI, so no limitations.
For the video assets, do you mean for sprites or for GUI?