This episode is nothing but filler. I don't mean that nothing big happens, that is okay and sometimes good, like in Breaking the Ice, but here there is no character conflict and no character development. You don't leave the episode knowing the characters any better than when you arrive (except for the fact of doubtful importance that Malcolm likes pineapples).
Malcolm has so far been an anti-character. We know nothing about him but his name and function. So it was at first a welcome fact that we would get an episode about him. The problem is that throughout the episode we don't learn anything new about the character except for the fact that apparently no one knows him well either. I guess this happens in the real world, people go by life without leaving a mark on anyone, but this makes for a hell of a boring character.
I was also at first happy that we get to spend some time with Hoshi, she is very charming and played by a very good actress. But we get the same problem: there is no character growth and we don't get to learn anything about her. They could change Hoshi for any random Enterprise crew member, give the same lines and go out with the same effect. What a waste!
About the A plot, the threat of the aliens seems real, and it manages to keep the episode from being downright bad. But since we don't get to know absolutely anything (really, we don't get even a single line from them) about these aliens, it is very hard to get any emotional weight on this issue. It is mildly entertaining, but can easily be skipped for something with real substance.