Hey I just gave this a few play throughs, one I made it pretty long. Overall this is awesome! Super fun take on pinball. All of the sounds and particle effects are really good. I love all of the upgrades and the progression. And squishy is the best! Here are a few notes I wanted to give:
-Sometimes, it seemed like the ball would slip through the paddle? Like the collision wouldn't register? For the most part the physics seemed great, but I saw this every once in a while. Though it might have just been the speed, and I missed the hit
-On the first level I didn't really have any trouble tracking the ball, but when I went to the second level, sometimes this was really chaotic and I'd follow the wrong ball. That may be by design but i wanted to not it
-When getting upgrades, when I would click something the first time, it wouldn't work (no reaction), but would work the second time.
-Your method for coming out of the upgrades and showing the direction of the ball was really good. Sometimes in similar games coming out of the upgrades leaves you unprepared to react, but I always felt like I knew what was happening.
-I don't know if this is already the plan, but adding some sort of meta progression would be fun where you can purchase things (I know there's already been discussions about purchasing different color themes). Also of course more upgrades and levels would be welcome as well! (maybe these get unlocked and i just haven't reached that yet).
Anyway, this is really fun with a lot of potential for expansion. Good work!