This game is a love letter to a genre that hardly even exists anymore, and never really did on PC. It really plays like a GameCube 3D platformer, and would feel right at home on that system. It doesn't quite have the same strong identity of some of the classics, but it's still a real breath of fresh air, and if you feel nostalgic for these kind of games you have to try it. It's 10 - 12 hours of great lighthearted fun, through vibrant and varied worlds brimming with charm and creativity.
My main issue with the game is that the imitation of the classics extends to the way the game plays, for better and for worse. The controls aren't as tight as they could be; traversing across smaller platforms can be really finicky, and it can be hard to judge your jumps, dives and climbs, resulting in falls to your death that you won't always feel are your own fault. The camera is very old fashioned too. Left and right camera movement works fine, but moving the analog stick up and down simply moves the camera closer or further away, rather than tilting it up and down. This is rarely a problem in combat, but it does feel archaic when you're just exploring and trying to find things, and can cause some annoyance.
Another minor problem I have is that the game doesn't always give you a clear idea of what to do next or direct you to what you're missing. On one of the worlds I had no idea how to unlock new chapters until I googled it. The last world doesn't give you any clues at all, and instead just drops you in there for you to work things out yourself. It's not a big problem, and perhaps I'm just impatient, but I'm not 13 anymore either, and I don't have time to just aimlessly explore until I figure out what I'm supposed to do. I don't need my hand held, but I do need a little more direction than this game was sometimes willing to give me.
So it's not perfect, but it's a very fun and satisfying game, not to mention adorable. Leaving each session of playing a game with a big smile on my face is something that doesn't happen nearly enough these days, and that alone makes me want to recommend A Hat in Time.