In summing up (ha!), phase is not just a potential problem in audio engineering. It’s actually one of the essential components of sound alteration. We’ve only touched on some of the most basic theory and techniques here. It will serve a budding engineer well to dive even deeper.
I’m happy you think it sounds varied! Of course, I’ve been freaking out for awhile about the exact opposite; when I listen I of course hear a lot of similar patterns, progressions and melodies, which worries me a bit. Ultimately, I try to maintain a sort of “been there, done that” mentality to writing new music, meaning that if I find myself venturing into too-familiar territory I look for ways to steer myself towards a new direction.