Two Castlevania games in one cartridge. Castlevania Harmony of Dissonance focuses on Juste Belmont and his quest to rescue his childhood friend, while Aria of Sorrow focuses on Soma Cruz, a teenager with occult powers.
The two games are both side-scrolling platformers, but they have a lot of differences. Harmony of Dissonance is more like the original Castlevania, while Aria of Sorrow is more like Symphony of the Night.