For anyone wondering like I was, the level cap ends at "Hero" with +90 to all stats. I suggest playing normal mode until you cap out, and then move to survival, it will make things a lot less frustrating. I went with arielaquino's suggestion of ninjas x2, robot x1, cat x1. Put two ninjas diagonal from each other and fill in the empty spots with the cat and robot (it makes for a better spread) Spam spacebar nonstop. Put all into Candy stat with the exception of putting 1 into magnet every couple levels (to accommodate for increased need of dodging). Next max out attack>health>speed>special. Using this strategy I got 30k by the end of level 16.
For survival mode you do NOT need to save all the toys for a gold rating, just beat all 25 waves. I kept resetting the game every time I lost a toy, until I tried just beating it. ಠ_ಠ
 "They Took Our Candy"){kind=icon}
 "Demons Took My Daughter"){kind=icon}