The 4th Unit Series: Merrygoround

Merrygoround is the sixth installment of The 4th Unit series and a sequel to D-Again, being the second chapter of the Einheit story arc introduced in the previous game. Koshinaka's research of the data bank on board the Diabolique, a stealth aircraft carrier of the United Nations, is aimed at increasing the life adjustment factor of bionic soldiers. However, members of the Einheit assault the laboratory, and the bionic soldier Blon-Win must decipher the clues left in order to proceed with the research and confront a mysterious person named Rua Rip Salisbury in the Original Matrix.

Gameplay-wise, this installment is a departure from any format introduced in the previous entries. It is essentially an interactive movie with semi-animated voiced cutscenes occupying the bulk of the game. The player is required to choose the correct character and perform the correct action within a time limit during each scene. Failing to comply with the time limit will subtract a small quantity of the "Life" bar, while choosing a wrong action will normally reduce it by an even larger amount. Once the Life bar is depleted the game is over.