The Thunder Force series (サンダーフォース, Sandāfōsu, also spelled Thunderforce) is a series of scrolling shooter type video games developed by the Japanese software company Tecno Soft (except for Thunder Force VI, developed by SEGA). The games are known by fans of the genre for their hardcore appeal, pleasing graphics, and generally well composed synthesizer-based soundtracks.
The first game appeared in Japanese computers, such as the Sharp X1 and the NEC PC-8801 MKII. The majority of installments in the series appeared on the Megadrive onsole, where the series gained much of its popularity. The most recent entry was released on the PlayStation 2.
The setting of the Thunder Force series (excluding the fifth chapter) are centered around the war between inhabitants of the Galaxy Federation, and the ORN Empire. The games feature the "Fire LEO" spacecraft series, developed by the Galaxy Federation under "Project Thunder Force" to be small, but maneuverable and powerful fighter craft. The Galaxy Federation feels that these ships have the best chance of defeating large forces such as the ORN empire's, as opposed to sending a host of larger ships.
Thunder Force V details the discovery of Galaxy Federation technology by Earthlings and the consequences this discovery causes, leading to a battle between Earth forces and the ORN Empire in Thunder Force VI.
Early games in the series had multi directional scrolling, overhead stages where the player would attack airborne and ground targets. These stages were later removed in favor of horizontally-scrolling stages that contained various gameplay elements derived from popular horizontal scrolling shooters like those in other well-known shoot 'em ups such as Gradius, consisting of an array of interchangeable and unique weapons, satellite turrets which provide the player additional firepower, and level design which encourages player memorization and skillful ship maneuvering and positioning in order to effectively pass.
- Thunder Force (1983-1984)
- Thunder Force II (1988)
- Thunder Force II MD (1989) (Sega Megadrive/Genesis port of Thunder Force II)
- Thunder Force III (1990)
- Thunder Force AC (1990) (Arcade port of Thunder Force III)
- Thunder Spirits (1991) (Super Nintendo port of Thunder Force AC)
- Thunder Force IV (1992) (Sega Megadrive/Genesis) (Released in the US as Lightening Force: Quest for the Darkstar)
- Thunder Force Gold Pack 1 (1996) (Sega Saturn) (2-in-1 Pack containing Thunder Force II and Thunder Force III)
- Thunder Force Gold Pack 2 (1996) (Sega Saturn) (2-in-1 Pack containing Thunder Force IV and Thunder Force AC)
- Thunder Force V (1997) (Sega Saturn)
- Thunder Force V: Perfect System (1998) (PlayStation) (Port of Thunder Force V)
- Thunder Force VI (2008) (PlayStation 2)