This game reminds me a bit of Sweet Dreams by Papillon or of Bitsy games. Basically, you control a character on the screen and you interact with objects by hitting the space bar. Then you get some text or possibly some options.
It's a relatively short game, but well-done and polished. Your grandfather never lets you up into the attic, but you've sneaked in and now you're going to discover the truth for yourself. The relationships depicted are by turns heartwarming and heartbreaking, and there are definite funny moments (like the expressions grandpa makes when you ask very personal questions).
The game's only fault, to me, was that it was fairly brief, giving a limited sense of interaction. I don't think a game has to be long to be great, but I feel like this game didn't fill up the full size of its concept. I did enjoy it, however.