It was a Ghibli film released last year, it only spans 17 minutes and it was a funded by Disney as a crossover film. Let me just say that it is the most derivative thing Ghibli has done and it tarnishes their reputation as a studio.
Movie is different and different movies have different stories. The 1978 series is the best, then watch the original film series, then the Y2K era series (Cosmo Warrior Zero et al.), then the 2013 film. 2013 film is just a tech demo, though.
woo!