Did you acquire a game in a big bundle, or for free, which you didn’t intend to play but did anyway and ended up loving it?

Mine is undoubtedly Heaven’s Vault. A story rich, very slow, puzzle game that takes you to different locations to solve linguistic puzzles. Asking you to slowly decipher and learn an ancient language. Even though the puzzles are very similar all throughout, the constant attention it demands and clues you naturally discover keeps them interesting. So interesting in fact that you might even go back to previous puzzles in order to apply your new knowledge to discover even more, despite the game never asking it of you. It is one of very few games that has given me the sinking feeling as I approach the end, which granted it a rare seat in a special steam category in my library of too-many hundreds of games.