Thunder Force AC was released in December 1990 in Japan. AC stands for 'ArCade'.
This game is a port of the Sega Mega Drive game "Thunder Force III". The main changes from the home console version are:
-No stage select screen
-Stages are shorter.
-Slightly different enemy layout.
-Some graphics are changed, including title screen.
-Many voice tracks added.
Developed by Technosoft.
Nintendo Super Famicom (1991) "Thunder Spirits"
Sega Saturn (1996) "ThunderForce Gold Pack Vol. 2"