Clipping through planets is a known issue. At the moment, the laser will only destroy the target planet. It won't destroy any non-targets that pass through the path of the beam. I'm not sure if it's an issue that's being worked on, but it's just how it's programmed to function at the moment.
Currently, that is how I programmed it work at the moment. There was talk of changing it at some point.
Personally, I prefer how it works now. If at first look, it's more logical and more important it seems more fun to destroy all planets on the path. The consequence is that you can destroy one of your planet by accident without really control it. If the annihilaser destroys all planets in its laser ray, the UI must be updated to be able to control exactly when we want to shoot.
Yeah, this shouldn't be fixed because it can easily lead to annoying mishaps like blowing up your own planet. Gotta accept some oddities for the sake of gameplay.
I think it should be changed, actually, just like planet smashing was. Actual scenario that actually happened: Player 1 was totally winning. He had planet A, moon B and superlaser C, all built and ready to go. He actually said, "How do you want to die" to the rest of us in the FFA. He had plenty of choices. He decided to throw the moon at us on planet D, which shared an orbit with planet A around a gas giant. Moon B starts up, goes into orbit around the gas giant on its path towards planet D and in the process clips planet A. Player 1 dies. He was standing on A where the moon clipped the planet. It was the best day ever. I could definitely see someone doing the same thing with a superlaser. They fire it and accidentally kill themselves on an intervening planet. The question is whether it should kill the first planet it hits or all planets in a line. My thinking: Kill only the first planet it hits. If it hits a gas giant or sun, the shot is lost. The creates a possibility for maps where a metal planet shares an orbit with another planet around a gas giant or a sun and it's the one planet that the metal planet can't kill because the gas giant or sun is always in the way. I mean, if this is a lot of trouble to code maybe it's not worth it but it would be awesome if it's not too tricky to change.
