Isabella's Fireside Music Challenge is a game on the Disney site and Disney channel site. It came out January 11, 2012. This game is unique in the fact it has Isabella as the main role, rather than Phineas and Ferb.
Phineas looking at the blueprints for the machine
Ferb gives a thumbs-up
Isabella says "What'cha doin'?"
Phineas says hi to Isabella.
Phineas explains what they are making.
"It has cannons......"
"And it is huge!"
Phineas needs someone to test it out.
Isabella agrees to do so to earn a patch.
Isabella and the Fireside Girls agree to help Phineas and Ferb.........