Peter Weller deserves to close out his career with more projects like Dexter and fewer like Screamers. Give him his due: he absolutely does not mail in his performance here, although there is something intangible about Screamers that makes it feel like it doesn't quite deserve a good Peter Weller performance. But there it is anyway.
Bear in mind the intangibility of why Screamers falls short. The tangible things aren't amazing, but there are certain things about Screamers that deserve at least a pat on the head. Most notably, the locations are pretty good. It's shot in cool looking rooms with fun lighting and sciency contraptions lying about. External shots are bedecked with fairly effective That-Big-Thing-Back-Theres — I don't know whether this is decent matte drawing, or decent CGI layering, but it's one or the other. Either way, it's not obviously hackish (the way the spacecraft shots from Leprechaun IV: Leprechaun in Space were). There's enough cool looking big concrete things the crew had to shoot around that I didn't find myself scoffing at the stuff that clearly couldn't have actually been there. And that ain't nothing.
Besides, it's a decent story, although I suppose more credit should be given to Philip K. Dick for that. Good dialogue, for the most part, as well. As I mentioned, Peter Weller delivers a believable performance, and that wouldn't have been possible if his lines totally sucked. The weakest the script gets is a conversation between two of the characters in which one harps on the others repeated use of the line, "Just get off my back." It goes on for far too long, and it gets annoying very quickly — all the more so because it's these two assholes doing the talking.
And here we arrive at why I didn't give this 3.5 stars. After all of the money had been spent on Peter Weller, location shooting, matte drawings, CGI, and stop-motion, there was obviously not enough dough left to hire guys that weren't these two. Way hammy, and in the case of the slick looking fool on the left, its an arrogant kind of hamminess. It's got nothing to do with believability. It's simply an exercise in patience while he's on screen. I had another pic I could have posted of him licking a knife, to illustrate the point — but blechh. You don't want to see any more of him than is absolutely necessary.
Not a bad movie by any means, but I wouldn't have had any reason to watch it if I weren't going for "Tech Gone Bad" as my genre theme this year.