By far the easiest level to get this trophy in is "On Burrowed Time" in "Avalonia".
This side level consists of you controlling the Hamstertron that you were introduced to in the first level of this world. All you have to do is follow the maze quickly. Remember to use "X" to jump and "R1" to boost.
This is so easy on this level that there really isn't much to explain. On my first try I got a 37x multiplier followed by a 12x multiplier.
The video below is not mine. All credit goes to TheVarietyGamer.