I think you've figured it out already.
1. light locks and shoot right ramp
2. shoot right ramp to lock balls, start modes, and start multiballs
3. shoot pop up orcs and spiders. Eventually you'll start/stack another multiball doing this.
That's it. The game is kind of neat but it needs help...big help...in the software department. Right now, there's nothing exciting about it. It's all about shooting the right ramp, which you can do from either flipper, and keeping the ball in play is very easy. The real problem is that there's no progressive, exciting scoring. There's no all or nothing, risk/reward shots. There's nothing to build toward, no exciting huge shots. The modes all score the same, and there's no particular reason to chase mode points once you've started them because you are better off just working toward and multiball.
To do well, just keep the ball in play which isn't difficult.
People putting up huge scores on this thing their first game isn't going to be a rare occurrence.