It is always fun to collect other spaceships and create a massive ship that can destroy anything in its path!
The game was really fun to play, the controls get a little weird when you combine many ships (like it starts rotating from a point other than the center)
I would also suggest to add a downside to having many ships, as otherwise there is no reason to not collect other spaceships you find. I also think adding game juice would double the fun (particles, camera shake and other good stuff)
Overall, an amazing entry!