Super Mario Dimensions is the follow-up to Super Mario World 3. The game takes place in a fully three-dimensional open world. Unlike OTL's Super Mario 64 which took place in Peach's Castle and the surrounding grounds, Super Mario Dimensions takes place in the Mushroom Kingdom, and there's a much larger area to explore, with dimensional rips connecting the different areas of the Mushroom Kingdom. The controls are essentially the same as they are in OTL's game, Mario can kick, punch, long jump, triple jump, somersault, wall kick, and more. The camera is controlled with the right analog stick and there are two different modes which are toggled with the directional pad. There's a free camera mode that operates much like the camera in modern open world games, with the player able to rotate the camera perspective with the stick. There's also a fixed mode, which operates similarly to OTL's camera. The game operates much like the original Super Mario 64 in terms of progression through the worlds, Mario collects Stars that can be gained via the completion of various level objectives. There are 180 stars total: 7 in all 21 worlds (including one red coin star, there are NO stars for collecting 100 coins in each world, ITTL, playtesters had more time with the game and concluded that finding so many coins to earn a star would be too tedious and players could already hunt down eight red coins in each world for a Star, the 100 coin stars were replaced with another objective), one each for defeating Bowser in the first three battles you face him in (but not for the final Bowser battle), and 30 secret stars scattered throughout the Mushroom Kingdom for completing various objectives. The prize for earning all 180 stars? Being allowed to go through the game as Luigi and earn all the stars again. For getting all 180 stars as Luigi, the player is given a special reward: meeting Yoshi on the roof of Peach's Castle and earning an infinite Wing Cap that can be used to explore the Mushroom Kingdom at will, along with 150 extra lives.
The plot of the game is fairly simple: once again, Bowser kidnaps Peach from her castle. But this time, after Mario attempts to give chase, Bowser uses a special machine to create a dimensional rift that Mario can't pass through. However, Bowser's machine goes haywire and the entire Mushroom Kingdom is filled with these rifts to various other dimensions. In order to reach Bowser, Mario will need to collect Stars from various worlds, these Stars guide Mario through the rifts so he can travel the dimensions safely.
There are four different areas of the Mushroom Kingdom that Mario can explore:
Toad Town- (A bustling town full of Toads. The rifts have caused Toads to get sucked into them, Mario will need to explore the town and the worlds thoroughly to save them all. He can also get the Wing Cap and the Vanish Cap here once a certain amount of Stars are earned, 10 and 12 respectively, and once he gets 15 Stars, he can open a portal to Bowser's first lair.)
The worlds that can be found here are...
- Bob-Omb Battlefield- Same as OTL.
- Whomp's Fortress- Same as OTL but with a second, slightly smaller tower that can be accessed via cannon.
- Jolly Roger Bay- Same as OTL.
- Sky-High City- A massive cityscape full of big skyscrapers and fast moving cars. Donkey Kong makes an appearance here.
- Cool Cool Mountain- Same as OTL, but the penguin mom has a husband that Mario needs to find.
- Monty Mole's Hole- A huge complex of caves dominated by Monty Mole enemies. Some of the Montys are friendly and once Mario gets 15 stars and one star from this world, a friendly Monty Mole will guide Mario to Bowser's first lair.
Pipe Hills- (A hilly plain full of pipes and secret passages. Mario can find the Metal Cap after navigating a perilous pipe maze. This area of the Mushroom Kingdom has some of the game's only old-school 2D style platforming.)
- Big Boo's Haunt- Same as OTL, but with some friendly Boos you need to rescue.
- Mecha Metal Factory- A gigantic factory world with lots of moving parts and Mechakoopa enemies.
- Hazy Maze Cave- Same as OTL, but without the Metal Cap.
- Lethal Lava Land- Same as OTL but with more areas inside the volcano.
- Shifting Sand Land- Same as OTL, but the pyramid has a bit more to explore.
- Dire Dire Docks – Same as OTL. You reach Bowser's second lair pretty much the same way you did in OTL's game (requires 40 Stars to reach him in this game). After defeating Bowser, you take a boat from here to Mushroom Bay.
Mushroom Bay- (A seaside beach area with lots of swimming and secret coves. There are mermaid Toads living here.)
- Ancient Antiquity Land-A land based on Ancient Greece and Rome, with many temples and statues.
- Wet Dry World- Same as OTL, but looks a bit more like a cityscape, kind of Venice-esque
- Angry Angry Sun- Another desert world like Shifting Sand Land, but dominated by sunlight and featuring wide open plains and many dunes, and the return of SMB3's Angry Sun enemy.
- Tall, Tall Mountain- Same as OTL.
- Tiny-Huge Island- Same as OTL but with more old-school Mario enemies like Fuzzies and Buzzy Beetles.
- Tick Tock Clock- Same as OTL. Once you have 70 Stars here, you need to climb all the way up the clock to open a warp to Bowser's third lair. Once Bowser is defeated there, you can access Peach's Castle.
Peach's Castle- (Pretty much identical to OTL's Super Mario 64, though instead of 15 worlds here, there are only three.)
- Strange Weird Land- A mysterious world dominated by psychedelic colors and strange phenomena, with lots of physics tricks.
- Rainbow Ride- Same as OTL, though there's the addition of a huge rainbow dragon that Mario can fight to win a Star.
- Space Chase Place- A huge space world where Mario can move from planet to planet in somewhat similar style to OTL Super Mario Galaxy.
After getting 100 Stars, including at least one from Strange Weird Land, Rainbow Ride, and Space Chase Place, Mario can access Bowser's final lair. Somewhat like Mario World 2, it's a twisted, dark, fiery version of Peach's Castle full of enemies and obstacles that Mario must navigate to reach the final battle with Bowser. In this game, the number of times Mario has to throw Bowser into the mines surrounding the arena (similar to how you beat him in OTL Mario 64) depends on which Bowser you're facing. The first time you face Bowser, you have to throw him once. The second time, you have to throw him twice. The third time, you have to throw him three times. In the final battle, you have to throw him SIX times (and it's much harder than IOTL). After Mario defeats Bowser, he and Peach use the power of the Stars to fix the Mushroom Kingdom, sealing up the dimensional rifts. Then, Mario enjoys a nice big cake baked by Princess Peach and gets a smooch on the cheek.