The Girl Who Leapt Through Space is a curious bit of anime brain candy. It has a little bit of everything thrown in: mechas, school life, teen angst, fan service, high tech, moe, slapstick, plot and the like. The scifi setting fills the visual landscape and the renderings are actually rather entertaining, but the show never really takes itself seriously enough - i can quite tell yet if it is meant as pure . There isn't anything particularly special about the series, but given that it is scifi but not too technical (like Planetes), action packed without being one long fight scene (like Bleach), fan servicey without being ecchi (though the female pilots all seem to wear cleavage suits), and has enough story to progress without being heavy, the series makes for an enjoyable light watch. It certainly isn't an anime classic, but if you are into any of the above genres and want a light mental snack, this isn't a bad choice.
Don't be confused by the title, The Girl Who Leapt Through Space bares utterly no resemblance to the similarly English named Girl Who Leapt Through Time.