You can simply spam heelflips and endlessly accumulate points and, accordingly, a multiplier. Literally three minutes of heelflips is enough to get over 2 million Score . You just need to get into a hole where your character won't fall and won't hit anything.
Perhaps a limit on the number of repeatable tricks could be introduced. For example, a maximum of 10 heelflips in a row, after which the multiplier simply stops accumulating until a new trick is performed.
Barrel Prototype
