Nostalgia may have me biased, but I remembered getting the trial for this on my laptop as a kid, and managing to find a disc version to install it. Was nice to find it available as a download later in life. I've never played Diablo so I don't have the obvious comparison to make, but it's a fine, if dated, dungeon crawler where you work your way deeper into a dungeon completing quests for the town. The final floor has a boss for each dungeon, and each game has all previous games' content included. This is game 3 out of 4 I believe so it includes game 1 and 2 in their entirety inside it, giving you ~5 dungeons to explore.
That said, because each game includes the content from the previous games, you should probably grab the latest one (Fate: The Cursed King) instead to get more bang for your buck.