Cave Story is a freeware Metroid/Castlevania style platformer. It is a massive platform adventure along the lines of Metroid, Castlevania, and Terraria. With a long engrossing storyline, a hard but not frustrating difficulty level, and a beautiful setting, the game is perfect to sit back and lose a few hours with. It was originally released on the PC for Microsoft Windows in 2004. Over the years, it has been ported to the Nintendo Wii, DSi, 3DS, Mac OS X, and Linux.

The Raspberry Pi port is possible because the original Cave Story engine was reverse engineered and a new open source engine called NXEngine was created.