The Land that Time Forgot by Edgar Rice Burroughs.
In 1916 the US Montrose is fired on and sunken by a German U-boat. However the survivors manage to sneak aboard and capture the U-boat. In between subsequent coups, the British and Germans agree to an uneasy truce until they can reach a neutral port. But they become lost and instead arrive on the mythical continent of Caprona where dinosaurs and cavemen still roam.

Giant mushrooms and treasure chests are ripe for the picking, but Carl can't gather them on his own. Can you guide him through each level - pushing rocks and smashing crates along the way?

Unga Bunga is a multiplayer platform/deathmatch hybrid for 1 to 3 players, in which the players run around as club-wielding cavemen in exotic habitats, kill moose and bears to gain technology (which allows them to use better weapons, including spears, traps, firesticks, coals, bow and arrow, sword), fend off invading philistines, and ultimately compete with eachother for various objectives (depending on the game type).