Accelerate Away From

App Surge

An attribute (B) that will be like accelerate toward, except the opposite.

RThurman

You can use a move behavior in an actor:
Direction: vectorToAngle( self.Position.X - game.Mouse.Position.X , self.Position.Y - game.Mouse.Position.Y )
Relative To: Scene
Move Type: additive
Speed: 10*(300/magnitude( self.Position.X - game.Mouse.Position.X , self.Position.Y - game.Mouse.Position.Y ))

You can mess with the "10" and "300" until you get the right amount of repulsion from the mouse.

Hope this helps!

Clouds

. . . or simply make your 'accelerate toward' values negative.