TwinBee

As in other games in the series, you can gain power-ups after defeating certain amounts of enemies by shooting the magical bells they leave behind. The amount of times you shoot them determines the color change and thus the power-up granted, such as multiple shots, options, etc.

If correctly powered-up, both ships can join-up to perform a screen-clearing attack. You can choose your starting stage from any of the first four stages (the fifth and last remaining locked until you clear all the others).