Bat Boy is a 2D side-scrolling action platformer where players assume the role of Bat Boy. The interdimensional mage Lord Vicious has brainwashed Bat Boy's sports-hero teammates to compete in the Trials of Darkness. Bat Boy must traverse hostile environments with the crow Garou to free his teammates, acquire their unique skills, and confront Lord Vicious. The game includes baseball-style combat and traversal mechanics.
The game presents nostalgic 8-bit visuals and a chiptune soundtrack. Players will battle brainwashed teammates like Racket Girl and Mr. Blitzer, acquiring their powers as they progress through diverse regions. Environmental puzzles and baseball-bat-based traversal are key gameplay elements, alongside numerous enemies and hidden secrets.