These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Idiot Plot: The kids have to retrieve some technology from Earth to save their planet, so rather than send scouts to find this technology, the aliens send a bounty hunter to stop them rather than help because they really want to invade our planet...
It's stated it's not their entire planet that wants to invade, just some of it. Sending a bounty hunter is considerably less risky than sending soldiers who might reveal you.