Okay, well, let me get out of the way the really obvious thing: it sure was convenient that Kirito was a hacker who could understand the language of
The Matrix Cardinal and could convert Yui into an in-game object on his first try on an insane deadline! I mean, not that I'm necessarily doubting that he's a pretty hardcore geek... but how would he even know the commands?
I think it would be a bit better if, rather than "hacking" they could have just done something like shown her be converted to an object that was then going to disappear and he grabs out and saves it or something. It conveys the same point without being quite so... lulzy? to anyone who actually knows anything about computers. (This is like what someone who doesn't understand computers thinks about people who are good with computers -- they type at a million words per minute and magic happens that's beyond understanding!
)
Anyway... that aside, I enjoyed the episode. There sure are a lot of parents who bought this VR game for their kids!
Probably will have more to say in a bit, but will re-watch first...
Edit: Having her be converted into "Yui's Heart" is actually a pretty clever call-back to Episode 4 with "Pina's Heart". But I suppose that, because Yui's not a familiar, that same trick won't "revive" her.