Size-Changing Effects in Super Mario Bros Wonder

Super Mario Bros. Wonder is 15 months old now, and as is usual for games this far out, the hype around it has died down. But this video, and its information, has been in my to-post file for a long time, so let’s get it checked off of my list.

In Super Mario Bros. Wonder, every level has a “wonder effect,” a sometimes-optional event that changes the gameplay in some surprising way. Like the Piranha Plants might start singing and marching through the level. That kind of thing.

There is a level with a boss fight against Bowser Jr. where he makes himself really small (accidentally), then really large, and the player’s size changes to the opposite: really big, then really tiny. The player’s physics change to reflect their new volume.

As it turns out, this effect is, in a way, faked. During this whole fight, the player’s size doesn’t change at all! Instead, the room changes size, and the camera is zoomed in or out so it’s not noticeable. Junior’s size actually changes twice as much. The changes to the player’s physics are applied on top of this state.

Rimea on Youtube made a video, like a whole year ago, that applied the Wonder effects from the boss fight in normal levels, and the player’s character doesn’t change size at all there, there’s the physics changes and that’s all. Then they put some other objects in the room, some question mark blocks, and they change size along with the room, making the camera gimmick a bit more obvious.

Here is their video explaining and demonstrating how the effect is done (6m). Why is it implemented like this? My guess is that the player movement routines in Mario games are really complex and detailed, and any time when it comes to a decision whether to change it or something else, the developers do everything they can to not mess with the precise and exacting parts of the engine, for fear of breaking some other obscure part of the game. The player program has to be used throughout the whole game, while the boss and its room are only used in one part, so it risks breaking fewer things to put the changes all on them. That’s how I see it, yeah.