when you instantiate the explosion particle effect you should also consider a Destroy(gameObject) on the ship imo, and perhaps give it an extra second or so before the Game Over pops up. On the Game Over canvas or panel or whatever you are using you could consider adding a fade animation to it, and changing the opacity from 0-1 whenever that gets enabled. I think that would just add a bit of feeling to that game over moment but again just my opinion. Game is looking great, and I really love that particle effects package. It's one of my favourite asset packs and its also in my jam submission that Im busy with.