Different: Both Good and Bad
For me, the heart of ‘tower defense’ is strategy. Gorg is a well done game, and has some new elements which are always nice to see, but it’s a little to twitch for me. You have to constantly move your towers in their orbit. This is the biggest difference, and IMO, it’s not a good one. I can see how some would like it, I’m just not one.
It’s also a bit annoying that you’re limited in where you can place your satalites and at the same time, the incoming paths are not defined at the start. This makes it both impossible to plan ahead, but you’re still penalized for making the wrong choices.
That being said, the secondary features of the game are top notch. There’s good tower variety, the different types really do make a difference. This includes an excellent array of support towers. The research and money resource management aspects are also well done. They add richness while staying simple.
Zanerock about Unstoppable Gorg