Impossible to discuss without spoilering:
I kind of assume that the name of this game, Keepsake, is play on the name "Memento," which of course is a movie that told a story in the way similar to the way this game tells a story. I don't actually intend to spoil Memento, since most people know the part that's pertinent here: the primary conceit is the story is told backwards, which is how Keepsake goes about doing things, as well. So Keepsake is what you get when you put Memento in a thesaurus, and, make it interactive... kind of.
At the beginning of the game - which is actually the end - you have shot someone. Your actions from then on don't have much effect on the ending of the game, which is already in progress, but they do have an effect on your overall game score. The game will rate you on how nice of a person you were before you shot the person you shoot, but you have no control over the part where you shoot that person, which is played out for you. Basically, you play out the actions that you took up to that point, backwards, until the moment when the game starts (which is actually where the interactive part ends).
If that's confusing, go ahead and play it, because it really only takes a couple of minutes.
Now during play, what I found most confusing what I was and wasn't allowed to do at certain times. I spent a lot longer than I probably should have trying to pick up the angry old man's cane, which, as it turns out, you can't do. What you have to do is take a happy man's cane away from him, and put it on the ground, which creates the angry man. That's because that's the good action that you can take, played in reverse. When the game goes back and plays it in the right direction, you'll pick up the cane and give it to a grateful man. So after you puzzle this out, it makes a lot more sense what you're actually doing in the game, but until then I spent a lot of time typing "get cane" variations, and it's always a little irritating in IF when two items in a room are essentially the same and need an adjective to differentiate them. With this particular execution, there's no way around that.
I think as an experimental thing, it was all right. For some reason I felt a little hollow about the way it ended (began? no, ended.).