I liked it, the little details when the balls hit the circle was really satisfying. The thing that i found quite weird was that the ennemies actually goes up even when in the middle of the line. I found it weird mostly because they move from left to right across the width of the map (it bug my brain a bit don't know why so take it with a grain of salt). Also adding a spawn point at the opposite side could have make the game a bit more chaotics too i thinks. Having shape going at two opposites directions.