It pushed the boundaries for what was acceptable for a kids' show at the time, with a lot of gross-out, scary moments, and innuendo.
The first 12 episodes or so don't have any gross-out.
Catchy theme song.
Flapjack can be annoying sometimes.
K'nuckles can be unlikeable at times.
Despite the theme song's lyrics, the characters never made it to Candied Island, therefore, ending on a cliffhanger
There are some REALLY disturbing moments, such as that closeup of a scary cat and K'nuckles' nightmare. It also got up to the point where even kids to teens to adults have claimed that they had nightmares.