The sheer amount of regard the adults in the series for the girls in the Alien Party is little to none, and absolutely none of them feel any empathy when they cry, scream, and even eventually die.
at one point three side characters seemingly become addicted to being possessed by aliens, saying they've been bored ever since they were released from the alien's control and only finding joy in re-becoming thralls.
[SPOILERS]
While no animals actually die, however, the aliens in the storage room, who ARE designed after real animals, are slaughtered via Yuri's dead Borg in Episode 2.
there is a moment in episode 2 where a character is framed like they are about to fall to their death, but they end up saving themselves and perfectly fine.