Let's separate the game into two branches; one is the message and themes of the game, and the second is the actual game/gameplay that is used to convey the message.

So the ideas of negative thought processes and depression are obviously quite important ones, and the themes of mental health and promoting good mental hygiene are presented well and in a more or less sensitive and empathetic way.

The problem is that the game itself isn't that good from a gameplay perspective; the character locomotion is janky and our protagonist will frequently get stuck on just about anything because of how movement and hit boxes for furniture etc interact, the puzzles are fine in the first chapter, unwieldy in the second, and positively obtuse in the third (where you will have to type in words in response to cues from objects and people) relying almost on reading the game designers mind to figure out exactly the one word which he wanted you to guess.

So, this is an eventually bright and colourful (initially drab and washed out) puzzle game with a fabulous theme and message, and increasingly lousy puzzles. Which means it isn't very much fun. Which means it kinda fails as a "game".

So, A+ for the message but a D- (at best) for the gameplay and attendant fun factor. Not recommended.