Hey, If you want some really easy credits in like 8minutes here's how.
If your level 9 or 11 which can be achieved very easy, all you do is go
to the theater and click "Get Prize" Usually the ad will only be like 30
seconds long, that mean when you reach your full amount of rewards per day,
you end up with like 10,000 credits, and probably 30-45 nova gems.. You
will get 450-475 credits every time you watch a small ad!