Thunder Force AC

Thunder Force AC is an arcade port of Tecnosoft’s 1990 Sega Mega Drive game Thunder Force III to the nearly identical Sega System C2 hardware, produced jointly by Tecnosoft and Sega.

The port is mostly identical to the console version. Some level layouts are altered, the level select and level intros have been removed and continuing starts you where you died instead of at the beginning of the stage. Furthermore, the game takes advantage of the System C2’s µPD7759 ADPCM chip, providing a larger number of voice samples and sampled sound effects — similar to the original X68000 version of Thunder Force II (even borrowing some cues).

Thunder Force AC