Remember that really great overworld presented in the original Legend of Zelda game and just how many screens it went over. Well the idea of the overworld is set for implementation into Hyrule Warriors. The goal presented by the overworld is to start at one point of the map and complete objectives to be able to unlock the entire map of course each segment of the map places you in a battle set in the Hyrule Warriors world and having to complete set objectives in that area as part of the battle such as defeat 300 enemies in 10 minutes. Adventure mode sounds like a while lot of fun with a whole lot to do and plenty to achieve as well as the added addition of further longevity to the game.
Lets just hope Hyrule Warriors is actually fun so this mode actually has a use but either way it does sound good and will surely be a good showing of side content.