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!