I have been waiting for this game since I was 5 years old! I am super happy with the stylized levels and outfits, and the entire game is very cute and fun. Of course, Nintendo had a lot of ground to cover after the (sexist, and honestly underdeveloped) failure that was Super Princess Peach, and in comparison this game is a breath of a fresh air.
To start off, this game is beautifully designed. Peach's outfits are to die for, she looks amazing in every single one and I really appreciated the attention to detail, the costumes and the variations on her classic dress are all fantastic. I would say that there are a couple gown designs that feel a little silly, or thrown together, but the fashion for each of the main gameplay costumes could not be better. Peach is my fave game character of all time and I couldn't be happier with her representation in Princess Peach Showtime. The levels are also so clever, bringing to mind the Paper Mario series' incredible artistic direction, and the perfect use of theater based visuals was so adorable and creative. The levels are very very cool, but I wish they were slightly more traversable, I love exploring the nooks and crannies of Mario games.
As far as issues go, I understand and hear the complaints about the difficulty. I am a fairly seasoned Mario player and I found this game to be fairly easy. However, I like the amount of challenge it provides, and I think it is accessible and fun for all ages. I'm hoping in the future Nintendo will include the ability to change the difficulty setting for games like this, I believe these games can be fun for everyone without having to sacrifice quality and challenge for adult players. I will say despite the difficulty I still found some challenge in the game and had a total blast playing it. One of the biggest problems I had with this game were some of the auto controls that hold your hand occasionally (for example, the basement cowgirl level when trying to jump from ledges to the horse carriage) where you should be able to use your own timing so long as your given a good window to react, and jumping feels robotic and not as organic as other Mario titles. But, that being said, I think the levels are well designed and amazing to look at, with many fun mechanics, that any minor issues with controls can easily be overlooked, because you're so charmed with the gameplay and fun level design.
The other biggest problem with this game is the length, which you could argue is a compliment! I want more Princess Peach!! I suppose you could also say it's a criticism of how easy the game is and that I got through it quickly, but I will say that this does not feel like enough content to justify the price tag. I wish we were given a couple more levels and a couple more outfits to match, and some more mingame/B plot gameplay, but for everything I did get, and for how happy this made me and my inner child, I have to give it 5 stars. Nintendo, please give us more Princess Peach games!!!