That was fun.
Some neat retreads of classic Dwarf character points/prop nods: Lister being aware of his own lost potential (cf Justice, Inquisitor), Rimmer's incompetence at engineering/command and his inability to see women as human beings, talking vending machines, Holly, JMC, Zero-G Football, old VHS style tapes (didn't they used to be triangular though?), punishment by withdrawing a right to oxygen, Lister's guitar, etc, etc.
"Pree" was great concept for the computer; I really enjoyed her interactions and her demise was in keeping with her core concept too. In fact, I'd have loved it if she joined in with Lister's final logical point mid-sentence, so they complete it together, just before she deletes herself.
It's still not quite perfect RD though. A few things felt off: The Cat's scene with Lister just before Lister goes into the dentist's, the computer dentist/Dr himself (they should have played him less zany), the whole Chinese Whispers subplot (Lister could have worked out how to defeat Pree without it), the 90 hours/minutes gag (would have worked coming from Holly, but not from the more competent Pree).
I'd also have liked a final video from Lister-as-dad telling himself he knew he'd figure out how to win. And then for Lister to ignore him and go back to being a slob. Red Dwarf at its best managed to weave in a moral to an episode, before poking fun at that moral, and Lister acknowledging both his potential and his laziness and showing he's happy with both would have been a nice & amusing epilogue.
A good episode overall, mind. I think it still feels like it's trying a bit too hard at present, like they're all working hard to prove they can still do it. But it's absolutely on the right track and I have a feeling the series X episodes will continue to improve, and if there's an XI, that will be even better. If last week's was equal to the worst of S1-6 and better than most of 7/8, this week's is now into the last third of S1-6 eps. Definitely enjoyable!