Bomb Rush Cyberfunk - Unlocking Franks
On Versum Hill where the train passes overhead a Frank will be roaming around with his BMX, if you catch up and talk to him he'll challenge you to make 3 Million Points in 5 minutes.
I managed to do so by using constant boost tricks (BOOST + ANY TRICK) while on the rails which gives you a high point boost and if you do it while sliding it will reset your slide bar.
If you win, you will be able to play as Franks