One of the first IFs I ever played. I then thought it was fantastic. Upon replay, with many more games to compare it to, it can still hold its own.
Spatially, it's a small game. A house, a garage and a garden (where the eponymous Glowgrass grows. Beautiful image.) The feel of the game is larger though, thanks to a sort of VR-device you find in the house. The heart of the story, the backstory of the people who once lived in the house is to be found there.
Not much puzzlewise, nothing that a curious mind can't handle without hints. (and one small how-do-I-phrase-this-so-the-game-understands puzzle).
Good moving story, well recommended.