What should I do to improve this song?

based of Ctelin's RPG Soundtrack!

<p><iframe width="100%" height="180" src="https://embed.notessimo.net/?oembed=1&url=https%3A%2F%2Fnotessimo.net%2Fs%2F69265" frameborder="0" scrolling="no" seamless="seamless" sandbox="allow-same-origin allow-scripts allow-forms allow-popups allow-popups-to-escape-sandbox allow-presentation"></iframe></p>\n<p>What should I do to improve this song?</p>\n<p>based of Ctelin’s RPG Soundtrack!</p>

Darkness (unfinished)