It seems that Super Monkey Ball: Banana Blitz HD will have more than just monkeys on its roster, as a datamine of the demo has revealed that a classic Sega character will be appearing in the game.
The original Super Monkey Ball: Banana Blitz was released on the Nintendo Wii in 2006, where it used the Wiimote as a motion controller for the balancing aspects of the gameplay. The series had been dormant since 2014 with the release of Super Monkey Ball Bounce for mobile games, but it has been revived with the upcoming release of Super Monkey Ball: Banana Blitz HD, which might lead to new games in the series in the future.
A demo of Super Monkey Ball: Banana Blitz HD is currently available on the Japanese Nintendo eShop and a Twitter user named NWPlayer 123 has datamined it for content that might appear in the retail version of the game. It appears that Sonic the Hedgehog will be a playable character in Super Monkey Ball: Banana Blitz HD and that the rings from his games will also be appearing as collectibles.
The datamine also revealed that there will be ten Worlds in the game and that the player will need to complete Worlds 1-8 without using a continue to unlock World 9. The player will then need to complete World 9 without using a continue to unlock World 10. If the player completes World 10 without using a continue, then they will unlock the final character in the game.
Super Monkey Ball: Banana Blitz HD is being published by Sega and AiAi the monkey has appeared as a playable character in several Sega crossover games, so it's no surprise to see Sonic show up in the series. Sonic seems like a natural fit for the Super Monkey Ball universe and it's easy to imagine him running around one of the stages collecting rings instead of bananas.
Super Monkey Ball: Banana Blitz HD is due to be released for Nintendo Switch, PlayStation 4, and Xbox One on October 29, 2019. A Microsoft Windows version of the game is planned to be released at a later date in 2019.
Source: NWPlayer123/Twitter