As someone who has followed you for years this was quite the emotional experience. Had you been another creator, I just would've quit the game, but I held out thinking you would do something to make up for it. I played that last level for 10 MINUTES (i don't know what it must've been like before) just because I wanted to make sure you didn't just end the game will the dude killing himself.
Even besides that the game is borderline indefensible. You are playing someone who suffers from depression and depict them doing everything they can to not be happy. The most frustrating part of the game literally has you dodging happiness. WTF dude. I would like to say you were trying to do something good, but it came off as teenage angst that in the end just forces you to lead the embodiment of misery-guts to kill himself.
Touch on serious topics, fine, but put some thought into it man. You are more creative than this.
Here is my recommendation. Have a game where the gameplay feels like the emotion you are trying to present. Also, have a sad story that ends on a happy note. Maybe it is just the ones I've played, but your games have a tendency to get you invested and then just ending suddenly with "yep, life sucks. Period. Bye."
Keep on keeping on. I know your best work is ahead of you. I don't want to be mean, I just thought I would let you know.