Very good adaptation of a classic sf short story, "Mimsy Were the Borogoves" by Lewis Padgett (pseudonym used by sf authors and spouses Henry Kuttner and C. L. Moore). Some changes, of course, updating it to present time (story was originally set in 1942, published in 1943), expanding the story a bit -- but overall, nice work.
I thought the kids' interactions were very true to life -- sniping and fussing at each other and at the same time being close and loving. Especially liked the little girl's interaction with Mimzy, dressing it in doll clothes, having a tea party.
Very enjoyable.