To be fair, part of it might be due to the fuzz they made in advance about that episode: How fantastic that new writer is, so fantastic even that they asked him to write another episode! How it's an alien planet that's not filmed in a quarry! And the first reactions that I saw were all "OMG, Matt Smith's acting! Fantastic!"
So yeah, maybe my expectations were a bit high, after all the last ep and the Christmas episode were all fun, so maybe DW had finally found its mojo again.
Sadly it didn't work for me. The street scene reminded me of the one in Turn Left, which would be okay, but even more of Star Wars. The aliens looked like they came straight out of the Mos Eisley Catina. The "moped" looked like a speeder bike to me at first, but my boyfriend pointed out it's actually more like the thing Flash Gordon used. Now I know cheesy and I generally like cheesy, but all of that together was just too cheesy.
The story... oh well... let's not talk about the god that was a sun that disappeared afterwards, just puffed out. Must be great living in eternal darkness.
Also let's just ignore all that space/atmosphere stuff, who needs that. Asteroids have enough mass to hold an atmosphere, I'm not Sherlock Holmes, I know my astronomy... NOT!
Oh well, it's Doctor Who, it's not supposed to be scientific, so let's forget about that.
So Matt Smith's acting during that "1000 years of memories" scene. Oh my, there were tears! He must be a good actor! I looked, I really looked, and I had the feeling that most of his face didn't move. I give him that he might have acted with his eyes, but as this scene wasn't a close-up on his eyes, I can't really say. Vocally it was alright. If I had had my eyes closed, it would have sounded alright. This is officially the first scene where I thought "David Tennant would do this better, no David Tennant would ROCK THIS SCENE." Don't believe me? Watch the "Satan Pit" 2-parter. I had so many flashbacks to those episodes...
Now this is only my opinion. I'm happy for you if you liked it. I'm actually very happy for you, because liking it is so much better than not liking it when you WANT to like it.
So next episode we have the first Alien movie on a sub? Let's see where this goes.