LucasGM14 and 13moths pretty said everything there is to say, but here it is. The old man dying when he reads Walter's future is implying that Walter's future was to commit suicide and that there was not anything beyond it. That's a terrible message. The instant someone you love dies, you might as well kill yourself because there no way that you can ever feel better? Then after the main character dies you get a medal called "loved"? What the hell kind of message is that? That may not be your intended message, but that is how it's presented so you might want to change it.
Old man offers to see Walter's future, suddenly clutches chest and keels over.
Walter: I have no future.
Whoa, what the crap, Walter? *tries to move him around to help the old guy* That's it, I have to just walk past this dying man like I don't even care? I don't care how sad you are, Walter, you can call an ambulance! The man had future-vision that he used for good! He was helping researchers find a cure for cancer! He ran a puppy orphanage--probably! Old guy, noooo!
Walter at the grave: Why did this happen?
I dunno, Walter. Maybe Katy had a heart attack in the middle of the park and no one called an ambulance because they were all too sad! Did you ever think of that, Walter?!
Okay, got that out of my system. The visual design is okay, music's good. Dialogue could use some improvement, as the weak grammar kind of distracts from the story. Maybe find someone to help if you struggle with English.
When you've got a game with very little actual gameplay, the story really needs to be exceptional, and I'm afraid this... isn't. I know I'm biased because romantic portrayals of suicide really bother me, but if you're going to walk players through something like this with no other option, there should at least be more exploration of this specific character and what's driving him. Does he really have nothing else to live for? Those other people at the funeral certainly seemed to care about him, but maybe they're all manipulative, abusive family members just acting nice because it's a funeral, and that's why he doesn't care what they say. Did Katy offer some form of support and he's too afraid to learn to live on his own? Did he have suicidal tendencies before she died, and this was the last straw? I just need /something/ beyond "Wife dies. Sad husband kills self." Like that's just the way it goes. Putting together a puzzle (perhaps with a literal puzzle of memories for the players to solve, that could add to the gameplay without taking players out of the story) makes for a more satisfying experience.
I feel like there are two things that could have made this a great story-based game: 1) Answer some of those questions. Explore just why, exactly, Walter doesn't even consider going on without Katy. 2) Give the player an option on whether or not to commit suicide. When you can make a choice, it's a bit easier to get invested than when you're just following a script. And the "continue to live" option doesn't necessarily have to be a cute, happy ending! Choosing not to commit suicide can actually be a difficult, even scary choice when you're depressed. Exploring that can really add to character development and the overall story.
Overall, there's some potential here, but it needs more thought put into why people act the way they do to carry the story. Maybe consider including more options for the player.
Did I just make my character commit a lover's suicide just so I can get a five point achievement?
WHAT IS WRONG WITH ME?
This game is one of the best that has happened in my life.
Not wanting to be mean, but you should either make an alternate ending or take this out of the internet. Seriously, if someone that lost someone really close to them and is planning on committing suicide sees this they may just go ahead an do it.
I get your point, they got together in the afterlife, but did he really have to kill himself? He should instead have seen her ghost as he was about to jump and then turn back and cope with life until the day he died. They'd still be together in the end...
It's just that the message of your game ended up like "If you can't cope with your problems then just kill yourself".