There is a cap to how many objects can be present on the map. The shooters generate objects so when you're near that cap, they stop functioning properly. There's your logical answer.
Yeah. I was a bit amazed how quickly the cap was reached. I need to carefully plan the usage of extra objects in the further levels, or at least handle erasing the magma balls properly.
There's an object specifically for removing lava balls that hit it, use that to avoid hitting the cap.
Wow, I didn't even know that! Thanks. I didn't think there were too many tricks left at this point.
Wow, me neither! Is that object an obstacle too, or can it be found from another set of objects? What does it look like?