First of all, congratulations on making your first game! I think you've got an interesting base here, wanted to leave some constructive criticism you could use to polish this idea up.
1. The physics feel great and the ball bouncing is the most fun part about it, so I think leaning into that more is the way to go. Having different level designs that get harder and have more of a strategy to placing blocks (perhaps with hazards that stop the ball when hit) would give a degree of progression that would really round this out. You have the two different block types but they don't feel like they really make a significant impact since you can just keep bouncing basically infinitely.
2. Upgrades are great incentives, but I don't see a real reason to get anything that isn't the launcher or the speed/points increase. Even going to the next level lacks a strong incentive since it makes the level bigger, and therefore harder. Narrowing the design to the most fun parts of the game and incentivizing the player to play those ways can be done in a lot of ways. Maybe new levels provide bigger payout, a second ball, different shop items. I think the more interacting elements you can bring in that either are part of the level and opposing the player, or are new ways the player can build their own ability to win are the way to go.
I hope you continue to work on this idea, I think there's a really fun game that you could make if you keep at it!