It's good, be aware not to follow into the repeat problem, where you have a good sounding section, and replay it again and again. Variety can be good, and will make a good sound stand out more.
Somewhat like the Main transformers track called "Bumblebee". The main theme only comes in at about 2:45 and finishes at 3:30ods. But the track is 4mins long. The rest creates a mood and build to the theme coming. Sometimes having that theme, effect or sound and building around it is a good way to go. If you want to go horror, the build up in Say the Psycho iconic theme is about 2mins in and only about 20 seconds long. Yet it's what everyone remembers.
Creating tension can also be enhanced by slowly increasing a tracks speed, or dropping in and out of tempo changes. Keep it up!
True variety and build up can be important for a song. But this goes mainly for stand alone songs like singles or main themes. Not every song HAS to have it. Since so many songs have variety, to not have variety for a change is a form of variety in itself.
You're mot the first to compare this song to the Psycho iconic theme. It's because of the string harmonics isn't it? Believe it or not, but when I came up with the song I played it on piano. I had to get it out of my system so I turned it into a song I wanted to use for two purposes. 1 for a film I was making (unfortunately it was never finished, but I intend to remake it some day) 2 use it as introduction song for a demo album (that album is finished).
For the film it had to follow what happened on screen, so I was a bit tight up. It wouldn't be a main theme, just a short piece for tension. It does however contain a melody of a recurring theme. Not the high strings though, but the part of the clarinet and the tubular bells. And that part is very short relative to the entire song, and there is quite a long build up towards it. It's about a woman Juno (nicknamed the Waterbringeress) who decides to poison a doctor by giving her a glass of drugged water. The part with the clarinet and the bells is derived from Juno's theme song. I also uploaded that song. It's called Het Motief van de Waterbrengster, which means The Motif/Motive of the Water Bringeress. It's here on Newgrounds as well.
For the introduction of the album I thought it would fit because it reminded me of the intro song of the 2nd Gorillaz album Demon Days. I thought it be cool to have something a little like that.
So that's my defense. I agree with what you say though. I'll keep it in mind for any tension building song I make in the future. Especially if it's a main/iconic theme.
It was supposed to be scary, not make you laugh... Oh well.
Please contact me if you would like to use this in a project. We can discuss the details.