Easy game, just requires a little attention on your part. Best tips from me:

• Always play the Classic game. The one I played was Karat Craze or something like that. Gives 8xp/dab which adds up quickly.

• Always play 4 cards. The game auto-dabs your 3rd and 4th cards, so you don't have to switch back and forth.

• Always play at the higher levels, like super or premium. They cost more, but it is easier to get the collectible items to get extra credits, as well as collect more fish to get passive credits.

• Don't bother with the minigames other than the free spin and free slot each day. They don't give much experience, and a lot of them require you spend credits, which aren't worth it.

That's pretty much it. It took me 3 days. I probably could have done it in 2 days, but I played it very passively. Easy 2000sb that dropped into my account right away without having to pend.