Galactic hero Serena S has been trolled on Spacebook. This is obviously a cause to embark on an epic quest to punish the troll in question, who just happens to be The Space Prince. Guide Serena through 7 stages of shmup action, jumping, shooting, and yet decidedly more jumping and shooting to her ultimate goal of total testicular annihilation of her foe. Ultionus is a love-letter to the home computer arcade games of the late 80s and early 90s, particularly Halloween Harry, Astro Marine Corps, Duke Nukem 2 and especially Phantis/Game Over II.