How to find the center of the galaxy in spore
It made me
feel smug 
"Grox can kiss my sweet ass"
How I did it: I was well surprised I got there. I thought I'd be fighting with the Grox for days or even weeks. But once you get the ability to destroy cities or even planets, the Grox aren't that powerful.
I didn't eradicate them (yet) but I punched a pathway through their space territory to the center.
Lessons & tips: Make sure you get 7,500 max health and lots of those health packs.
I got there on interstellar drive 3. You don't need drive 5. However you may run into dead ends and get very frustrated. I was lucky and got there without any dead ends at all.
Resources: Guide
