Excellent suggestions, and something for me to focus on as I make revisions. For winning the level, I made it so that if you're down to the last 8 bricks or less (I think that's the number I used), it just moves to the next level. That was always a pet peeve of mine with other breakout-style games I played, where the action would kind of slow down while you try to clear the remaining bricks. But I think I'll add a counter indicating the number of bricks remaining until the next level, or something like that.
Yes, the levels are infinite as the game stands now. They're procedurally generated, but are designed to get harder as you progress (that balance does need a little tweaking, though). So, no "winning" the game as of now. But I imagine to improve things in general, I will add a leaderboard, and the game will keep track of your high score, how many of the 300+ brick types you've seen, how many background levels you've seen, how many powerups you unlocked, etc. It actually never occurred to me to make an "end" to the game (I'm used to the never-ending games of old like Missile Command, where I made it past 1 million after a long time and then figured that's where I would stop since things weren't getting any more difficult at that point), but now you've got me thinking about what that would look like--might need a storyline of some kind, too.
Anyway, thanks for your comments and great suggestions. The fact that you got to level 12 tells me you played for a good bit, so that thrilled me as a creator. 😊