Thunder Force AC was produced by Sega/Technosoft in 1990. The gameplay is simple but challenging: shoot or be shot down. You start with TWIN SHOT and BACK SHOT, which can be selected during gameplay. By shooting down the power-up ship, you receive different power-ups. They are as follows: Saber S: upgraded Twin Shot Lancer L: upgraded Back Shot Wave W: weak, wide shots that penetrates through walls Firebomb? F: drops bombs that trail across ceilings and floors Hunter H: three-way, fairly weak homing shots Shield blue S: provides temporary damage protection There are also two CRAW units mini-ships, which can be collected, that circle around your ship for extra firepower and provide some form of protection. Thunder Force AC is a modified version of Thunder Force III made specifically for the arcades with reworked graphics - although still very close to what the Genesis was able to offer. Thunder Force AC puts you behind the cockpit of a lone starfighter out to destroy all the enemy forces of the Orn empire by clearing 8 enemy-infested stages set in various outer space locations. Most of the game levels are taken directly from the Genesis version with a few minor changes, though levels 4 and 5 are totally different - both in graphics and level design. The game gives you a health-bar and the ability to swap collected weapons on the fly, which can be obtained by catching power-ups and activating them whenever you want.