Carl The Caveman is a little rude and savage, so he can't find all the giant mushrooms anmd treasure hidden underground. That means he needs your help.
To achieve your aims in each level of Carl The Caveman, you have to help Carl push rocks in the correct direction (without any of them blocking any of the exits), break boxes that block your way, avoid the traps, etc.
Apart from capturing all the mushrooms and treasure, in Carl The Caveman you must open certain blocked doors, and so teletransport to another level.