You might ask, “What motivation for destruction could a giant boulder possibly have to go on a gravity-powered killing spree?" That's a fair question, one that Adult Swim's Giant Boulder of Death attempts to answer. You see, a pompous general has turned your loved one into a statue of himself. So, in a fit of rage, our rocky hero decide to roll down a hill crushing everything in his path.

The game follows the endless-runner formula of play, upgrade, and then play some more. Tilting your iPhone or iPad will steer the boulder. You gain points for everything you hit that isn't a military installation. You see, for a huge lump of rock you're surprisingly fragile. Slamming into a spiked wall or homing mine will end your descent.

Instead of completing the usual trio of missions, you only tackle one goal at a time. Completing it will unlock more buildings and creatures to smoosh, which will deliver bigger bonuses. There's also a multiplier bar which increases each time you hit certain thresholds. Once filled, your boulder becomes the Invinciball, a rolling dervish of unstoppable destruction.

Of course, the Invinciball status wears out rather quickly. And, since there is no window of adjustment when you turn back into a boulder, often you'll be gleefully rolling over everything in your path when you return to your native form - usually directly infront of a spiked wall.

As the game is free, the progression feels a little slow, presumably in an effort to encourage you to spend real money on upgrades. As a result, the need to repeat levels to grind out currency does impact your enjoyment. The yodelling that accompanies the game over screen and Invinciball state also loses its charm due after the 30th death.

The quirkiness we've come to expect from Adult Swim is present here, but this idea doesn't feel as fleshed out or well-considered as Monsters Ate My Condo or Robot Unicorn Attack. It's fun for a little while, and costs nothing to give it a try. But unlike the mighty boulder that sits perched upon a hill, this game probably won't be able to whether the ages intact.