No physics collision

Hello, I’m trying to do a game which has boosters like in buנble ball, but I didn’t succeed to detect a collision without using physics.How can I do it?

https://www.youtube.com/watch?v=CpAoxFwos-Y&feature=youtube_gdata_player
Like in here 0:30 when it changes gravity after colliding

Thank you all!

The arrow in 0:30 may have been set as a sensor (Look for isSensor)… These objects detect collisions but do not affect the object that collides with them.

The arrow in 0:30 may have been set as a sensor (Look for isSensor)… These objects detect collisions but do not affect the object that collides with them.