The game is mostly a trek through colorful landscapes of the mindscape. It's creative, playful, with nice tunes and songs, all while dealing with both positive and negative emotions. The gameplay itself isn't much. Listen to characters speak, walk some, fight someone, walk some more, solve a puzzle, walk. Then do some backtracking. The pacing heavily leans on the quiet segments rather than engaging ones. And due to simplicity of puzzles or the lack of any challenge in combat, those parts get done very fast. Maybe this game is better suited for kids. The presentation catches attention and the story has good lessons to teach about emotions, to the minds not yet jaded.
It was decent when it came out, but it did not age gracefully at all. It's clunkier than the very first Hitman. It feels and plays as if its contemporary to Codename 47. But it got released after the Silent Assassin and Contracts installments, to which it doesn't hold up to at all, neither in gameplay, graphics or controls. The redeeming feature of the game is that it's properly challenging if you're trying to play stealthily. There are multiple approaches to objectives, there's flexibility in how you tackle them. And the margin of error is razor thin regardless of how you decide to tackle a mission. But it always feels like you're playing a worse Hitman.