The game takes place in a massive multi-region world, with areas spanning from cities and neighbourhoods to the jungle and desert. The core gameplay is still the same; however, there are multiple people for Maxwell to help in each location.
Free-Play/Levels in Scribblenauts Unlimited
Free Play and Levels are undissociable. Unlike Scribblenauts, Super Scribblenauts and Scribblenauts Remix there is no level selection screen. All 30 - 40  areas are connected and visitable through a map, they house levels, are fully explorable and are populated with NPCs. For the full list of levels, see the article List of Scribblenauts Unlimited Levels.
Small missions in each area give you Starite Shards (around about 400 total small objectives) and bigger multi-stage levels remain in the areas but temporarily remove NPCs and Free Play elements, giving you Starites (around 60 in total). Object Shards are like mini achievements, where you earn one Starite Shard for completing each one.
Multiplayer (Wii U)
Multiplayer allows two or more players to join in Freeplay or Levels using Wii remotes as they take control of any onscreen object.
Players can share their Custom Objects online. In the PC versions of Scribblenauts Unlimited, Steam Workshop is supported for users to share their creations with other players. The Steam version also includes 25 Steam Achievements.
Maxwell had 2 parents named Edgar and Julie, they had careers as explorers before they settled down to have children. They had fourty two children at all, including Maxwell and Lily. They gave each of their children a special and magical gift. Maxwell received a special notebook, while Lily recieved a magical globe that took her all around the world (All the other gifts are not elaborated on however, leaving them open to speculation). But Edgar and Julie sent all their children out to face the challenges of the world since all these magical gifts made the children spoiled and mean. Because of this, Maxwell pulled a trick on a hungry beggar by writing down a rotten apple. The beggar ate the apple, but revealed that he had magical powers, and placed a curse on Lily that would turn her from flesh to stone. Maxwell learned that the only way to stop the curse was to gather Starites. However, to get these starites, Maxwell needed to earn people's gratitude by helping them with their various tasks. Therefore, Maxwell decided to use his notebook for good, and set out on his quest of travelling the world to collect starites, all to make things right again for his family . In the end, we learn that the beggar was actually Maxwell's father in disguise, and that he did what he did to teach Maxwell to be a better person. Maxwell and Lily forgave him, but not before they used his cane on his dresser, and you may see Lily saying for you to be also a better person, which is true, so help others and be nice!
Scribblenauts Unlimited has the addition of making custom objects that appear when a custom word is typed. From the released trailer, objects can only be made using pre-made object pieces in order to stay within the animation style of the Scribblenauts series.
The Custom Objects feature was originally used to create all objects in the other Scribblenauts games. It was created by Edison Yan.
Object Editing is not included in the Nintendo 3DS version.
Unlike the original Scribblenauts and Super Scribblenauts, Scribblenauts Unlimited has many more new features such as:
- Object Library: Although similar to the 'Resummon' tool in Super Scribblenauts where it brings back previous objects, the Object Library is Maxwell's Backpack and he can store objects, custom (Wii U/PC versions only) or original, in there for later use at any time.
- Merit Board: Each world is filled with hints. There is a new feature called "Starite Vision", an aid that will highlight all nearby Starites levels and Starite Shard puzzles.
- New memes: Nyan Cat, Tube Man, Cool Story Bro, Tentaquil, Bread Helmet Man, Business Cat, Inception Cat, Blue Screen Of Death, Porcupine Eating a Carrot.
- Improved Graphics: In ALL versions of the game, there are improved graphics.
- More Objects: In ALL versions of Scribblenauts Unlimited, 60 objects can be spawned and coexist on a single level hub at once.
- Nintendo Objects: Guest Objects from other Nintendo series (such as Mario , Link , Zelda , and Yoshi) are featured in the Wii U version. ONLY the Wii U Version. 
- Streetpass: The 3DS version of the game allows you to share solutions to levels using StreetPass.
- The game, though released on Nintendo systems in North America on 13 November 2012 and in Australia on 29 November 2012, was scheduled for release on 8 February 2013 in Europe but was then delayed a twice. It was eventually released on 6 December 2013. The reason for these delays remains unclear, especially as the PC version was not delayed a second time from it's 15 February 2013 release date. The first delay was caused by things "outside of development" according to Jeremiah Slaczka , and the second delay was caused by "last minute changes needing to be implemented" according to Nintendo . The game was nonetheless mistakenly released on the Wii U eShop on the morning of the 8th of February, before being swiftly removed at noon . This, along with the alleged fact that some suppliers recieved the game anyway and sent it, means that some people got their copy "early", meaning on the originally intended release date. It was also possible to get the game early on steam by illegaly bypassing the region lock on steam accounts, as early as the original North American release date.
- The title screen's BGM is a remix of one of the levels from the original Scribblenauts game.
- Every level/world in this game is named after a form of text or writing. (I.E. Payper Plains)
For the gallery of screenshots, please vist the Scribblenauts Unlimited Gallery Page.