That was fun, and if it'd been episode 5 of a full season it would have been great, but as a special, well I guess it didn't feel particularly special, also I'm not sure the time loops made complete sense, and for saying time was such a factor people spent a LOT of time standing around chatting.
Loved Dan decoying the Dalek "Dalek's do not have managers!" Bea was very good as well.
As for the Doctor/Yaz, meh, leaves me cold because I don't get any sense of feeling between them and I don't see why people would be disappointed that this relationship won't reach any kind of fulfilment. Of course it won't any more than the Doctor and Rose came to anything. It all feels very secondary school, even down to Dan's "My mate fancies you" moment.
Clearly Jodie and Mandip have chemistry, you only have to see them together IRL, but it's never translated into the characters having chemistry. In fact Yaz still doesn't have much personality. There's a random reference to the 4 years Dan and Yaz spent travelling, yet neither of them seem changed by this time. Yaz is the same character she's always been.
Anyway, the next special looks really interesting! Sea Devils! Pirates! China! Please let this be good, please let this be good, please let this be good....