On a deserted hot planetoid, a lonely robotic puppy tries to befriend an android visitor. His attempts at friendship are rebuffed until he is put a life and death choice. When the pup gives up his very own battery, his last hope comes from a within mysterious spherical chamber.

As your loglines part with industry convention and attract similar, if not identical, comments on a regular basis. It seems as if you haven't read (despite many recommendations) the Training tab on the top bar.

Here are a few pointers to help you in future logline drafts:

1 - Keep it short, ideally as close as possible to 25 words.
2 - Describe ONLY the main characters and major plot points of the story - protagonist, antagonist (if necessary), inciting incident, main action and goal.
3 - Stick to the following formula: After an inciting incident motivates a flawed main character, he or she MUST undertake action to achieve a compelling goal.
4 - Lastly, clarity is all - eliminate vague or generic descriptions.

Just curious, is the puppy the lead character?

On a deserted hot planetoid, a lonely robotic puppy tries to befriend an android visitor.

For the purpose of a logline that's the core of the plot.

>>His attempts at friendship are rebuffed until he is put a life and death choice.

Second act complications, part of the script of course, but extraneous to the purpose of a logline.

>>When the pup gives up his very own battery,

A critical second act, midpoint or thereafter, moment. ?But a logline should not reveal, hint or suggest that moment.

>>his last hope comes from a within mysterious spherical chamber.

This appears to be tipping the hand as to the ?3rd act resolution. ?A logline should ?never reveal, hint or suggest what the 3rd act resolution may be.

fwiw