Do Interrupt cards work against players playing as the aliens?
I'm assuming by &quot;aliens&quot; you mean &quot;intruders&quot; as the rules define &quot;Intruders&quot; as &quot;the name give to the alien organism by the ship AI&quot;.
If so then this is covered in the Nemesis FAQ

Can an Interruption card be played to stop an Action of the Intruder
player?
No, it can only be used against other Characters.