I'm not exactly sure how much if it is original and how much is an asset, but there's certainly nothing wrong with that. Modifying someone's code is an essential skill in gamedev, and you've demonstrated a good level of it. Good job!
Thank you! Give thanks to the creator of the asset I used as the base for this game, it saved a lot of my time. I mostly focused on adding features, like AI (which the original "AI" was placing pieces randomly) and power-ups, and some required modifications to the asset, and keeping level creation and stages control intact