the hardest fight imo was what im guessing was the brother/sister team. it took me about 5 tries to figure out that killing the sister as soon as i could was a really bad idea. kept her stunned the last time and dished out massive damage to her troll of a brother. ride and both forms of baba were really easy and i had no problem killing them the first time out. other than the balance issues, great game!
for lvl 30, just put the first piece as far over on the straight piece as you can, and if it gets stuck, put the second as far over on that piece... itll work every time