Really love the boss designs, although a bit hard to control the player ship at times, and some other time the squid boss went away and I couldn't find him XD but overall a good game grats also on the art department!
It can move out of the playing boundary, that's right. But you can lure it back by moving away from it. I thought about adding an indicator that points toward the Boss for this. Do you think this would've been helpful?