Uchuu Kyoudai: Itten no Hikari

If you've finished Space Brothers and are looking for more, this short might look appealing to you. While it certainly wasn't bad, there were large portions of recap, and the new parts didn't add anything substantive to the series. The main cast (including Hikari) aren't developed at all during the movie, and nothing significant happens that you wouldn't have already seen in the main series.

Unfortunately, this isn't a good primer for those who are curious about Space Brothers either, as the ending recap spoils some events in the TV series, and the odd combination of real images and CGI with 2D animation may mislead new ... viewers.

In short, if you're desperate for some additional Space Brothers goodness this could be a decent time passer, but otherwise there's nothing to see here.