Help the little fellow while destroying everything in his path, wielding your mighty cannon as both digging tool and weapon as you push ever deeper into each wondrous cavern. The goal is to collect gold by blowing it up. Not a sound investment strategy in real life, but in the game it's tons of fun.
Use the [WASD] keys to move and the mouse to shoot, jumping across chasms and tearing down walls in search of riches. Think of it as a browser-based Terraria, except with less resource collection and more high explosives.