Packing a game full of collectibles is a clever way of freshening up the core gameplay experience by introducing an extra challenge, while also adding a ton of replayability to a game for anyone who wants to try and reach the 100% completion rate. However, while it's not unheard of for many games to have a few hundred secret collectibles for players to get their hands on, some have taken it a step further and featured many more hidden secrets that can be uncovered.