Probably unity, this kind of game isn't too complicated. It's mainly making it feel good and look neat with graphics and VFX.
If you went for the pure browser way, Babylon.js would be your best bet. It has a bit of a learning curve, as you would need to implement base game features yourself but it wouldn't take too long for something like this.
I think both Unity and Godot have ways to compile to WebGL. I don't have direct experience with Godot, but in Unity this would be relatively simple to do.
If this was made with Unity it would load a lot slower and perform worse. Unity is not a good fit for web. Godot might be better, I'm not sure. PlayCanvas is an option.
