Math Slide: add & subtractv1.4

What changed

• SocialAdded a new collaborative multiplayer mode for up to 4 players
• SocialAdded a competition mode where the first player to finish wins
• New featureImplemented a shared game mechanic where players slide tiles into a middle zone

Original release notes

*** Collaborative mode ***
You can now play Math Slide collaboratively. Up to 4 players can work together to complete a game. Each player slides a tile into the middle and when all players have the correct tile in the middle, all players win. Players can also switch to competition mode, where the first player to slide all their tiles into the middle wins.