@buzz That has to be it! Thanks so much!

It's funny how our memories distort things over the years, for some reason in my mind the controls were like Tempest. Obviously not!

@AndersHP said in What's the name of this horizontal shooter?:

I guess it's a long shot hoping that this game will be playable on the Pi, right?

Well, it'll be released for the XBox One, Windows 10 and Steam. The hope to play on the pi remains on the Steam.
More info here: http://cupheadgame.com/

@AndersHP
it's not in either. you'd need to use lr-mame2014 or later via the experimental menu. i would expect it to have pretty poor performance on a pi3 but who knows.