I don't usually prefer speedrun games(mostly because I'm really bad at them) but this one really stood out to me with its evidently large amount of polish, its more accessible approach to momentum, and reduced emphasis on precision platforming. That said, I would personally like the platforming controls to be a bit more forgiving; there were many times when I jumped at what I thought was the edge of the platform only to find that I was already considered off of it, and could not jump anymore. Most platformers, especially ones that ask for precision like this, give a grace period after stepping off of a platform's edge where the player can still make a jump, and I'd like that in this game.
I was eventually able to wrap my head around the controls by the end, though I'm still not confident that I would be able to know which button to press if faced with a novel situation; something about using the same button for multiple actions makes that difficult. I'm not saying it's a bad control system-- it felt very smooth and elegant when I was doing well -- it's just that I'd perhaps like the option to bind a different key to each action. The change I definitely want is to remove shooting from idle stance entirely, as unless there's going to be a reason to do so in the final game, I see no reason I would use that ability and I would highly prefer pressing down to make me dash no matter what.
My BIGGEST gripe with the game is even a death animation as short as that is far too long for a game like this. I don't want to spend even half a second watching that death animation instead of starting the level over. It surprises me that this is an issue, because you have an excellent restart level function but inexplicably disable it during the death animation. Every successful speedrun platformer works to minimize the downtime of the player, and this just seems to stick out as a confusingly unhelpful decision in this otherwise great game. I would like to be able to reset during the death animation or have an option to skip them entirely.
My other, smaller, complaint is that the background layers constantly changing color sometimes blends in with the foreground at times. I'm not sure if that is intended or not, but that has NO reason to be a thing, especially because it hurts how clear the level design is and screws over the player. The most glaring example of this is the second double jump level, where an area that looks like a platform fades away right as you approach it, and it was hard to not think that was a dick move when it inevitably killed me the first time.
But I complain out of love. You've sold me on this idea within the short 20 minutes or so I've spent playing it. I'm very excited to see the full game!