Game description from the publisher:

Heap is the madcap game of vehicular mayhem where the player who cobbles together the most outrageous vehicles wins!

Each player plays a gang of crazed goblins that have traveled across the post-apocalyptic wasteland in broken-down vehicles to converge on a gigantic heap of long-discarded scrap – perfect ingredients for demented automotive modification. In arena-style bouts, each gang selects its champion driver to storm the heap and duke it out for the best parts to upgrade their vehicles. Be first to trick out your vehicles and dominate the final pileup to rule the heap!