Nice game, congrats!
I think you could make it a bit fairer if the enemies have friendly fire. Also, consider adding an explosion for those ships, damaging the surrounding ones.
Thanks for checking out my game! I think friendly fire is cool, the only problem is that the algorithm that determines enemy ship movement is the same for all of them and they all end up fusing together, which creates the strat of moving in circles and letting them kill each other. Turning off friendly fire was the only way I saw of fixing that. I really like the idea and feedback though!