Different costumes are better suited for some challenges
You may notice that each level gives you suggestions on what costume
you should wear. This isn't for no reason. Different costumes have
different powers or benefits and if you're performing a challenge that
requires you to have a huge Despicable bonus, it's probably best you use
the costume that extends the XXL Minion. This theory applies to lots of
other challenge and costume pairs as well. So if you're stuck on a
challenge, re-evaluate what you're wearing and see if a costume change
will improve your odds.