Sin & Punishment is a really good rail shooter for the N64 where you simultaneously control a character and your crosshair to aim at things
There's a lot of things on screen, I'm not sure how the N64 can actually do this without exploding
Basically you shoot and dodge stuff, your gun also has a built-in sword to slash things from up close and to reflect incoming missiles back at enemies
The story is about a lot of things.
You're the resistance of something, so you have to kill your way through monster-infested and enemy soldier-infested tokyo. Eventually what happens is that TOkyo gets flooded with a sea of blood and you suddenly transform into an evangelion so you can fight another evangelion
Then we switch characters to the girl, where we end up flying around on a block of concrete kept afloat with psychic powers while you take down an entire battleship fleet, a squadron of fighters with the boss of the enemy organization fighting you with it by standing on top of the fighter aircraft directly, and take down a flying Ace Combat-tier superweapon for good measure
All using your dinky pistol
Then some weird shit happens involving seeing your son from the future and the final boss being the clone of the Earth itself
It can't quite be explained with words, you have to play it for yourself
Thankfully it got released for the Virtual Console so Dolphin will run it at a silky smooth 24fps
Despite being originally a Japan-only game it only has an English voice over, which is cheesy