The game is more similar to the book (Roadside Picnic) although all three versions are unrelated.
Many people boil down the film to "brooding Russians walking around a forest babbling nonsense" but if you're in the right mood it's an absolutely beautiful film. Mood is very important for any Tarkovsky; if you don't go in with the right expectations his movies can be excruciating to watch.
What? The dialogue is second to none!