To get the desired energy into the theme, I switched to a techno-style bass line, using a Yamaha AN1x with lots of compression. I used a loop from a sampling CD, but compressed and distorted it heavily. I added two other loops from my collection to get the groove to burn hotter. When I layer loops, I prefer to have a main loop that is pushed up in the mix, and any other loops pushed back, just to add bite and feel. This works very well for me.
Hooks are very important in most styles of music.
The more distinctive, the better. But finding a hook is essential to making something memorable. It needs to be simple and to happen many times during the song. While my melody seemed catchy enough, it wasn't a hook, because in 45 seconds it only got to happen once. Not a good hook candidate.