I didn't mind the first hour or so. We get to know the crew, we see their interactions and the pressures that they are under. Even going to find Icarus 1 didn't annoy me too much, though there was no reason they couldn't have tried their bomb first, and if it didn't work, then try the other ship. Okay, I can think of one or two reasons why, but they were never stated.
No, what seriously shat me was the mad killer from the other ship. It felt like an afterthought - Oh let's put in a killer, that'll be cool! The film didn't need it. There were enough obstacles and issues for it to run beginning to end and be quite a reasonable film. It didn't need burnt, nudey, killer-boy!
Neither did it need him hunting down the two female characters. So many characters die, there was no need for both women to be hunted. I was already annoyed at the killer aspect, then he took out one woman, missed out with one of the guys, then went after the next one. What the fuck? Totally gratuitous and pointless.
Lastly, all the weird distortions and editing while dealing with psycho-boy... What the hell was that about? Seriously, for an important chunk of the ending I had no idea about what had just happened. A deleted scene explained one confusing aspect of it, but for the actual action, no idea.
All in all, it's quite a reasonable psychological SF flick that is totally fucked up by the addition of an insane killer for no very good reason.