I haven't actually played the game yet and will change the rating after I do, but I saw the comment about Unity losing save data when you update. I came up with a solution to that issue, and if you're saving data in PlayerPrefs I posted source code for a class to override it to keep web builds from change the saved data location when you update games - it's designed to be easy to just copy/paste into your project and let you specify a directory where you want data saved persistently from now on. If you're not using PlayerPrefs, this also includes a description of why Unity's web builds are suck when it comes to saving data and why this solution works, so it should be easy to cannibalize the code to use in your game. https://3p0ch.newgrounds.com/news/post/1086279
I wrote it four years ago so check the comments in case anything has changed with Unity web builds since then (I've become a Godot convert in the meantime).
Be aware that if you implement this, it will lose everyone's save data when you push that update, but for any more updates in the future the save data will persist. So it would only make sense to push if you might plan for more than one update. Or of course to include in any future web games.
I've played now and gud game, but I got the feeling that sometimes the double-jump got triggered when the player was still on the floor? I docked a half-star for that, but then added it back when I saw that raindrops on the main menu splatter when they hit the mouse cursor.