How do films like this get made? I'm sure that I'll never know. But somebody spent a fair amount of cash producing this nonsense.
The good: It's short? The bad: Everything else. There is no discernible plot of any kind. The characters actions make absolutely no sense. There's no exposition, no climax, no goal to achieve, and it ends as a cliffhanger. The acting is unforgivable. No part of the story makes the slightest attempt to follow a thread of logic. Kids are beating up/killing adults at every preposterous turn. The fortified camp of survivors on the planet's surface is essentially a ring of shopping carts pushed together with some cardboard for extra reinforcement. The dialogue is embarrassing for any genre regardless of expected audience. The special effects don't even make sense (is the "skyark" a few hundred feet above the ground hovering or in orbit? You'll never know; you'll never care). As a distraction for sitting through this dreck, I tried to think of a worse film that I've ever watched; all I could come up with was "Ski Patrol" ... maybe, but Ski Patrol at least had a dog that could fart on command which exceeds any of the talents in Battle for SkyArk.
The verdict: This is not worth your time, money, or effort to make sense of. It's simply one of the worst movies that has ever been made. It has absolutely no redeeming virtues. Nothing that could have been done to this film could possibly have made it worse - it is the low marker for judging movies. Imagine the worst anime that you've ever sat through being turned into a live-action film by a group of 5 junior high school students with a handicam... that is better than this by a factor of 100. Run away!