After completing the events at Hotto in the first part of the game and are heading towards Gallopolis, you will be stopped right before the head by one of those strange ghost-like creatures you’ve likely seen throughout the game. His name is Ickle and he wants you to help him, so upon doing so, you will be transported to the town of Tickington. The first thing you will notice is that Tickington is in 2D and there’s nothing you can do to change this, especially if you are playing the regular game in 3D. The main premise of this long sidequest is that you will be able to explore small areas of the past Dragon Quest games, do a little thing, then be done with that portion.
Upon first arriving in Tickington, you will have to go visit the mayor of the place, allowing you to freely explore the town. It should be noted that there are a bunch of jars and barrels you can break, but the contents of those are completely random. Also, changing screens at all will make those breakables respawn, so they can be farmed, but it’s not really worth it in the long run. The mayor is located through the doors in the northwest portion of the village and upon speaking to him, you learn about the true nature of the Tockles and that some deviant tore pages from the books keeping the history of other worlds.
Your goal with the Tickington quest is to basically find Pastwords and revisit those past worlds, fixing whatever anomaly there is in those locations. Not only will you sometimes find treasure chests with loot in the past worlds, but you will also be rewarded for completing each area. You will receive the first Pastword from Ickle, but the other ones can be found by speaking to certain Tockles throughout your normal adventure. A good portion of the past worlds can be completed as you find them, but others might require items from other locations. Also, you will need to complete Act III before you can complete all of the Tickington content.