The shooter genre, by definition:
a. You have something you control.
b. It fires bullets or a weapon of some sort.
c. You generally fly around or drive around and the screen scrolls either horizontally or vertically. There are exceptions to this one, but they are generally denoted by an additional sub-genre.
Those are the ONLY requirements needed for a game to be considered a shooter. These are the generally agreed upon requirements we use and triggerfin's catlist uses.
Ikaruga=Shooter / Flying Horizontal
And the whole black and white thing, that's called
innovation and it's the game's selling point. It's why so many people like it. If you don't like it than that's fine, but that doesn't change what genre it is. You must have not payed much atenttion whne you played it as bullets often come from ground-based turrents or facilities. Again, this is a staple in the shooter genre, although admittedly, this one over does it a tad.
Of course I don't consider tekken a fighting game, rather a flaming pile of marketing b.s. and I don't consider football games playable, much less games, so to each his own.
(No I didn't write that review, but apparently I have a mental twin as this guy always hit's my points dead center.)
Also, every single solitary shooter game I've ever played has enemies that generate at the same spot every time. As the others say, it's the norm, not the exception.
Tiger, for the record pacman is classified as a maze game, i.e. it created it's own genre, which shows just how good it is.