I'm well aware I'm not the first one to point out the lack of button remap but... It's kinda important I think, so it bears bringing up... But another thing that'd be nice on top of that is the ability to invert the camera's X and Y axis, (I personally vastly prefer inverted X axis for 3rd person games), and another thing that'd REALLY come in handy is a button to re-centre the camera behind Madeline, cuz a lot of the time your right thumb is just too busy jumping and dashing to control the camera...
Another thing right, I LOVE that you can play with the D-Pad, I found it more accurate than the stick for certain secions, but I couldn't help but to notice that like... When you walk to one side, the camera leans slightly to that side, and so does your movement, so when you're walking to the side you're also walking slightly downwards, which is something you have to correct for while platforming, which has led to A LOT of deaths, both from overcorrection, and also simply forgetting to correct, or even just dashing in the wrong direction cuz I was trying to correct for that slight downward movement... I reckon that maybe warrants looking into...
And another thing that threw me off was the silhouette from when you're behind walls and certain other objects, like, I get why it's there, but it's confused me several times, it made me think I was in front of something when I was actually behind it, so maybe an option to turn that off would be nice? Or maybe change the colour of the silhouette? (Or both?) Cuz like, a big part of why it was confusing to me is that the silhouette is the same colour as Madeline's hair, which is also the colour in her model that stands out the most from the background...
And then there's a few thigns that are like... Not really necessary, but Miiiiiiiight be nice to have, maybe? No presusre...
For one, the ability to play in windowed mode in a smaller window would be quite nice...
For two, the option to change the rendering resolution (cuz I wanna make it even lower :3c) and perhaps even the aspect ratio? Cuz a game like this is BEGGING to be in 4:3!
For three, perhaps an option to move the camera in 45 degree chunks could be considered? Just for that extra retro feel~ (And also maybe accuracy in the platforming)
And last, and DEFINITELY least, y'know... This kinda looks more like a DS game than an N64 game (which is part of the reason why I wanna make the resolution even lower and 4:3 lol) cuz like... Those textures aren't filtered... The N64 uses trilinear filtering for its textures... Mayhaps that too could be an option? And also like... The models are like, flat, with the shading baked into the textures/polys, and they have outlines... All those things REALLY bring out that DS feel... N64 games have more smooth per-vertex shading, and no outlines...
Whether you take up on any of my suggestions is entirely up to you of course, no pressure whatsoever, what is here is already pretty good! I just think it's could be even better with just a few tweaks and extra options, just my opinion though...
[Edit]
Honestly, I think you should really consider making this into a full game! Maybe some improvements could come then... Just a thought... But yeah, like, more of this with the wee lil' issues fixed would be quite nice indeed...