You've stumbled upon your wildest fantasy! A buried treasure in the deepest depths of a cave. 
But right as you begin to process what has happened, you hear shuffles coming from the darkness. 
You must protect your new discovery at all costs.

Use the arrow keys and the A button to choose and select start menu items. 
While in game, use the arrow keys to move your character, the L and R keys to rotate your character, and the A button to shoot. Don't let anything touch you or your treasure or it's game over! 
You will level up periodically after fending off a certain number of enemies. Killing enemies earns you cash which you may spend to purchase upgrades at the level up screen using the arrow keys and A button.
 Upon leveling up, the game will become more difficult: it will spawn more enemies and it will introduce newer, harder enemies to defeat. 
This game is endless until you die, more and more enemies will come until one finally slips through, so your goal is to survive as many levels as possible. 
Upon defeat, you may view the amount of levels you survived and return to the title screen.
 The user may press select at any time to return to the start screen (for some reason, this is keyed to my enter key, not my backspace key)