Shmup ability ideas?

I was going to mention Ikaruga's polarity system, but you seem to have that covered. (The enemies exploded into bullets so you can use the bullets to charge up your super meter.)

Ideas

 controlling 2 ships

mad skills [video=youtube;ToBdzV7w5Pc]http://www.youtube.com/watch?v=ToBdzV7w5Pc[/video]

 controlling way more than 1 ship / multiple paths

[video=youtube;n-JQx3gD9oM]http://www.youtube.com/watch?v=n-JQx3gD9oM&feature=relmfu[/video]

 melee weapon that can be use to attack and defend against small projectiles.

The ship has many different projectile weapons, but the person playing is only using the sword to beat the game.[video=youtube;JAQ3fw6Xe-g]http://www.youtube.com/watch?v=JAQ3fw6Xe-g[/video]