Spelunky

You play as an adventurer known as a spelunker. The primary task is to explore the caves, collecting as many treasures as possible, avoid the traps of enemies.

A spelunker can whip or jump on opponents to defeat them, can pick up items from the ground that can be thrown at the enemy. You can also set various traps and use a limited supply of bombs and ropes to move through the caves. A notable feature is that the levels are randomly generated and grouped into four complexes "areas", each of which has a different set of items, enemies, terrain types and special functions.