Saint Slayer: Spear of Sacrilege is a captivating NES-style action game designed for Nintendo Switch, set in the tumultuous late 17th century. Players take on the role of Rudiger, a former soldier who must confront the malevolent Father Pacer, who disrupts the peace by stealing sacred relics across the Holy Roman Empire. The game features a robust single-player campaign with 21 stages filled with a variety of enemies and intense boss battles, ensuring a challenging experience for players.

The game's aesthetic is characterized by stunning NES-era pixel art, complemented by an energetic 8-bit chiptune soundtrack that enhances the immersive atmosphere. Players can engage with the environment by befriending animal familiars and unlocking numerous upgrades and bonuses. With player choice at its core, the game encourages multiple playthroughs, offering different challenges and rewards based on the player's actions.