Ninja Pirate Cave Raid

You control a ninja, moving left and right through side-scrolling caves. The basic goal is to get to the end of each stage, but pirates stand in your way. Your primary method of attack is a jump; landing on an enemy defeats them. You also collect coins scattered around the environment. The levels are short and the challenge comes from timing your jumps to avoid hazards and enemies. It feels like a direct, uncomplicated arcade experience from a simpler time for browser games.