If you want this package to be lighter, you can uncheck the 'Demo' folder while importing.
If you want the demo scene to works properly, please import TextMeshPro.
SoundInstance
SoundInstance is a full audio manager which allows you to play any sounds easily and without having to always setup an AudioSource and writing the code for it. It's also a complete music handler for your games! Just ask it to play a music and it's done! It keeps the music playing between scenes and you can Play / Stop / Pause and Resume when you want with a cool fade effect.