Quartet 2

Quartet 2 was produced by Sega in 1986. (Sun Corporation of America published it in North America)

Human characters collect guns and power-ups to destroy a variety of robots in a space base. Defeat the boss character and collect the key to unlock the base’s door and move on to the next level. Up to two people may join in on the fun.

This game was released shortly after the dedicated Quartet. Quartet 2 is not a sequel but rather a conversion kit that could be placed in two-player cabinets. The only real difference between the two game is Quartet 2 allows up to two players to choose from the four available characters.
The game has side-scrolling action and a Gauntlet-like join-in type play. The four characters each have a different name and wear a different color. They are Joe (yellow), Mary (red), Lee (blue) and Edgar (green).

Your job is to basically find the end-of-level boss, and then defeat it to obtain the key that will open the level exit, but your task is made difficult by the planet’s inhabitants. Get the jet-pack to make it easier to navigate the level and shoot any inhabitants that get in the way. These inhabitants will leave behind something that you can get to increase your score, and the inhabitants will eventually regenerate. If any one of them touches you while you have the jet-pack, you land on the ground or the nearest platform, and have to get it again; and the same rule applies to the key.