Related 10 Open World Games With Amazing Side Quests These games have such immersive universes that the optional content ends up being just as good as the main campaign. We're going to take a look at some PS1 games with huge worlds that reward your exploration. Playing this game without exploring is a failure to dive into what the whole theme of the game is about. It also executed the open world concept far better than any in the game before it. There are hidden weapons to find, secret rooms, really useful shortcuts, optional bosses, optional objectives, crossing invisible bridges, and so much more.