Darwin 4078 (Arcade) special powerups

The Darwin series by Data East uses the "E" that I think stands for Evolution to power up your ship. If you stop taking them for a short time, your ship will revert to the previous "state" in the Evolutionary chain. If you then take another "E" symbol, the chain has been changed and you will notice all new powerups, like the electronical bird and it's darker version, The BLACK BIRD that will eat up enemy bullets, but you'll still die when crashing into other ships and the bigger enemy bullets (like the ones the bosses fire).

To turn into the Black Bird, get hit by enemy fire while using the regular bird ship.

The game also has some other cool stuff that's hard to figure out unless you know about them. Some enemies can be "paralysed" when you shoot them just enough and they will mount to the front of your ship. This will enhance your B button (ground based shot) with some powerful weaponry.

Once in a while a smaller version of the stage boss ship flies up from the bottom of the screen while emitting a series of orange blasts that if you get caught in them will turn you into a zany "core ship" that shoots round bullets in all directions of the screen. You can also eat enemy bullets with this ship, just like the Black Bird.