Defender

Get to the 25th wave, and capture a humanoid. Fly to the 25th line of resolution (the height your ship starts from) and any remaining enemies will change to "BP", Bob Polaro.

Fry until the game stars (automatically) with only bombers on the screen. You get killed, but don't lose lives (you may just have a lot of guys.. I haven't tried dying that much yet.)

If a Baiter is chasing you, position yourself so it is above you, screech to a halt and it will "land" on you.