Games like Bryan's Indie Collection

Games like Bryan's Indie Collection include Half-Life, Warhammer 40,000: Boltgun, Black Mesa, The Citadel, and Half-Life 2. We matched them by the tags players give Bryan's Indie Collection on Steam (Indie, Procedural Generation, Old School, Retro, and Sci-fi): closest matches first, and among equally close ones the better-known games.