Firstly, you have no idea how much nostalgia I had when I played this prototype of yours, it was very similar to the style of my game at the beginning, good times...
But focusing here on this test, I found the mechanics to be very solid and I really liked the physics of the game, when I got to the end I thought "that's it" which you can be sure, it's a good sign.
Now the path to go through this is...varied, so, I recommend you take a piece of paper and play some random ideas and little by little putting them together in a coherent way, just be careful not to make the same mistake I made, I ended up creating a very large and ambitious project, but, in terms of design skills I had zero skills!
So, that's it! I wish you good luck in this recent project was born, and I will keep an eye on it to see what it becomes in the future ;)