Portal Stories: Mel is a total conversion mod for Portal 2. Consisting of 22 levels with new environments, tough puzzles and a strong story. Complete with over 350 voice-lines, a full soundtrack, custom models, textures, particles and much more! The average playtime is 6-10 hours, depending on experience with Portal 2. All the puzzles in the mod can be solved with clever thinking, quick reactions are never needed.
It takes time, but it does get better each time!