A quick small update:
I've made some small, but significant changes to the level transitions. Watching people on Youtube try to smash through the beginner puzzles, I became aware that the transitions between levels could be a bit snappier. I've made a few changes:

There was a reason I had the level numbers showing as an intro to levels. It was, essentially, a loading screen, inspired by the original Mario. I have, however, removed the need for the loading screen. A quick fade to black is all that's required now. I also think the fade to black has a much nicer feel to it, improving the overall game feel.
As stated, there's a new brief delay before the final score appears, once you beat a level. I feel this increases the satisfaction of completing a level, giving you a moment to watch the fireworks and enjoy the feeling of success before the score appears.
The Ruins are still coming along, as well as a few other minor quality of life improvements. I've also been planning future game projects. Feel free to come over and keep an eye on some of these and chat about them on the new Discord server.