This is an extremely fun and simple game. And gives me strong Tetris vibes. The only thing I would love to see is more experimentation in mechanics that you have already established. If you are going to introduce more mechanics then I don't think you should change the current one. I really do feel like you have perfectly nailed the balance with it. Even though it goes infinite it is extremely fun.
And lastly I want to see more Tetris vibes. Give me those extremely rewarding dopamine shots when I break a connection of 6+.