Some fun demolition derby games are "Smash Palace" from AddictingGames.com and "Crash 'N Smash Derby" from BGames.com. In "Smash Palace," players compete in destruction derbies and purchase upgrades to get to more prestigious events, while players earn money by crashing into cars at high speeds in "Crash 'N Smash Derby."
Upgrades in "Smash Palace" include new roll cages, better steering control and more powerful engines. A player earns more cash for better upgrades depending on how well he does in each round. In "Crash 'N Smash Derby," players simply use the arrow keys to move. Every crash earns the player a certain amount of cash, while taking a hit reduces the number of hit points on the car, resulting in elimination from the race once depleted.