Enjoyable game! The characters were enjoyable and the plot was very silly but that's to be expected for a family game- but it makes it all the more fun :) The costume designs themselves as well as the enemy designs were excellent! I love the cartoony artstyle. I felt like the battle backgrounds were very synonymous, but I think that's mostly because I wasn't paying too much attention, similar color palettes and all that. I loved the different areas, with the mall coming to mind as my favorite section of the game.
The different costume abilities were fun to explore- I do wish that some costumes that didn't have any did. Their abilities in battles were cool! I definitely stuck to particular costumes and didn't change them out very much, but I did try almost all of them out. There are some costumes I expected to be a bit cooler (French Fries had an awesome disguise- just didn't hit as well as I wanted.) but I still enjoyed them all nonetheless. I don't remember any particular complaints with the battle mechanics, I love turn-based games and quick-time events so it's kind of the perfect game for me.
Aside from some "of the time" jokes, I think the writing's fine. It's not anything revolutionary but I don't anyone would expect it to be. Just silly!

A solid 3.5 out of 5 for me, a very good family game if you or a kid want to play it!