Multiplayer
2 player mode lets you play "The Blockheads" with a friend via Apple's "Game Center."
Each time you play in a game world you can choose whether to play by yourself or invite a friend.
Although the game offers "Auto-match" in the Multiplayer Game screen, majicDave has stated:
"Due to limitations in the way Game Center works I wasn't able to implement auto matching for multiplayer. I also couldn't disable the auto matching user interface. It's misleading I know and I hope to fix it somehow. But for now, the only way to play multiplayer is to invite a friend."[1]
To invite a second player their device must be on the same version of iOS as yours and they must have "Game Center" notifications turned on.
If the connection is deemed (by the app) to be too slow to handle voice chat it will be deactivated for that session.