This change in behavior has some very significant effects:
1. Damaging a child alien isn't rendered meaningless if you are
primarily attacking the owner. This could be especially annoying
with the miner bosses, which have tiny parts that are completely
impractical to aim at.
2. Again, for the miner boss: previously, you couldn't see how much
total health the ship had; the health bar only uselessly showed
whether or not you defeated half of the ship (which you could
already tell by looking at it). Now, the health bar tells you
how much more damage you have to do in total.
onpon4