I went cruising through a large portion of the games in mame the other day (about 3 hours or more) trying to find yet another game that I had played as a kid. I think I must have missed it somehow.
The game was two player one after the other
The game was a scrolling shoot em up, vertical.
You would fly over base like structures below whilst blasting stuff (hows that for a vague description

)
I distinctly remember when you picked up some power ups that you could get bolt on that appeared on the side of your ship.
Player two had to play downwards on the screen whereas player one played upwards.
The big think I remember is that at the end of one level there was a head like boss who you had to shoot in the mouth with a projectile bomb launcher when he opened it.
The reason I think I am having trouble locating this one in particular is because I played it when I was in spain (and almost twenty years ago) so even if I could remember then name it probably wasnt in english

Hope someone can help me find this one, especially as you did fantastically at finding that other game for me last time. You guys must have some encyclopedic knowledge